Like other species in this genus, this snail has a corneous operculum.
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This goat has corneous horns. Gastropod shell of Viviparus contectus with its corneous operculum in place Corneous is a biological and medical term meaning horny, in other words made out of a substance similar to that of horns and hooves in some mammals. The word is generally used to describe natural or pathological anatomical structures made out of a hard layer of protein. In mammals this protein would usually be keratin.
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The mineral is rather sectile, and consequently was earlier known as corneous lead, (German Hornblei).
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The word corneous is also often used to describe the operculum of a snail, a gastropod mollusc. Not all gastropods have opercula, but in the great majority of those that do have one, the operculum is corneous. (However in several genera within a few families including the marine Naticidae and the terrestrial Pomatiidae, the operculum is primarily calcareous, in other words mostly made of calcium carbonate.) Corneous opercula are made out of the protein conchiolin.
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The gizzard of Bulla is rather different from that of other herbivorous groups. It has three large corneous crushing plates and ancillary corneous spines, instead of just grinding plates. The crawling snails show prominent, frilled or lobed parapodia. Bulla species have a soft radula.
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Palpi porrect (extending forward), frons with rounded corneous projection. Larva with four pairs of abdominal prolegs.
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The shells are, as Pilsbry calls them, ‘waxen white’. Some specimens have the apex coloured, corneous or with a yellow hue.
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Mantle caves serve as pulmones. Operculum corneous and multispiral. Penis is oriented above the right tentacle. Sexual dimorphism is often recognisable in external morphology.
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The edges are simple, not thickened. The thin operculum is corneous and multispiral. The shell is nacreous, with delicate suffused splashes of brown.Dall, W. H. 1881.
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The spire is conical. The apex is rather blunt. The apical whorl is rather prominent, reddish, corneous or purplish, smooth and rounded. The suture is impressed.
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The spire is short. Its outlines are concave. The apical whorl is corneous, projecting, and rounded. It follows the whorls of the spire lirate, with scalloped sutures.
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The corneous operculum is dark brown, and its shape is fairly typical of the family Strombidae: a slightly bent sickle, with seven or eight weak lateral serrations.
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Its eyes are naked and without lashes. The proboscis is obsolete. Palpi porrect (extending forward) and evenly scaled. Third joint long and frons with a rounded corneous projection.
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Bulged out, as the whorls of some snails. Convoluted. Rolled together. Cordate. Heart-shaped. Corneous. Horn-like, as the opercula of some gastropods. Corrugated. Roughened by wrinkles. Costate.
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The wingspan is about 18 mm. Frons with a long flattened corneous projection more or less buried in scales. In the male, the head white and brown. Thorax pale brown.
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The wingspan is about 25 mm. Male with a cleft corneous ridge clothed with scales on vertex of head. Abdomen clothed with woolly pile. It is a stoutly built moth.
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The height of the shell attains 3.5 mm. The small, thin shell is narrowly umbilicate. The spire is globose-depressed, and conoidal. It is subtransparent, corneous or bluish white in color.
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The shell is narrowly umbilicated, flattened above, thin, pellucid, olivaceous corneous. The shell has 4½ whorls, that are rather flattened. The last whorl is not descending. The peristome is acute, reflected, white-lipped.
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The height of the shell attains 32 mm, its diameter 38 mm. The broad, rather solid shell has a conical shape. The spire is conic. The apex is generally eroded, corneous (orange colored).
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Male without a cleft corneous ridge on vertex of head. Antennae minutely ciliated in male. Forewings with pale brown, irrorated (sprinkled) and blotched with black. The sub-basal line is obscured by black blotches.
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The shell is moderately in size for the genus, without hairs and brownish corneous. The spire is somewhat impressed. The shell is umbilicated. The ends of the peristome are connected by a thin callus.
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PDF The shell has up to five whorls. The aperture is subovate. The operculum is corneous and concentric. Colour is usually yellow, olive green, brown, cream or white and sometimes may have darker spiral bands.
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Palpi porrect (extending forward), reaching slightly beyond the frons and thickly scaled. Maxillary palp dilated with scales and nearly as long as labial. Frons produced to an acute corneous point. Antennae of male thickened and flattened.
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The corneous operculum is paucispiral, and has an eccentric nucleus. The body of the animal differs from species in the family Trochidae by having no cirriform appendages of the foot.George Washington Tryon, Manual of Conchology vol. X, p.
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A genus related to Liotia, but without a varix to the outer lip. The species are few-whorled and spirally sculptured. Their umbilicus has an internal funicle. The operculum is corneous, concave, multispiral, with a spiral frilled lamella.
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The ovate aperture has a marked siphonal canal and a weak anal canal. The aperture is closed off by a thin, corneous, cerithioid operculum that is multispiral and almost circular. The outer lip is thin. The columella is concave.
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The conspicuously radiate color pattern and the sculpture, consisting of coarse granulose lirae with interstitial lirulae both above and below, as well as the wide umbilical tract and eroded corneous or orange apex, will serve to distinguish this form.
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The size of the shell varies between 3. mm and 11 mm. The umbilicate, thin shell has a depressed- conoidal shape. It is flesh-colored, with paler at periphery and below the suture, fading into corneous around the umbilicus.
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The deep umbilicus is partly covered by the tongue- shaped callus extending from the columellar margin. The body whorl is at its periphery round-angulate. The operculum is corneous. Memoirs and Proceedings of the Manchester Literary and Philosophical Society v.
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The height of the shell varies between 28–39 mm, its diameter between 34–42 mm. The rather thin, umbilicate shell has a strictly conical shape. It is light olivaceous or pale corneous. The spire is conical, with nearly straight outlines.
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The shell is perforate, ovate-conic, very thin, pellucid, scarcely shining, obsoletely and closely decussated by growth striae and delicate spiral lines. The shell is pale corneous in color, sometimes fulvous. The spire is conoid. The apex is rather acute.
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The color of the skin is blue-grey. Three shells of Daudebardia rufa The shell is perforate, depressed, transversely dilated, slightly striate, very shining, and corneous or rufous in colour. The spire is moderate and sublateral. The shell has 3 whorls.
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Interior of aperture strongly iridescent. The thin operculum is corneous, with many whorls (about 10). The outer surface is hollow, with irregular, radiating striae, which are more numerous and regular near the sutural line. The inner surface is convex, and very smooth.
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The shell of this species is orbiculate-globose, lightly striate, hardly shining, covered with a corneous epidermis. The shell is composed of 5 convex whorls. The spire is obtuse. The suture is hardly impressed, not marginate, bordered below by a blackish band.
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The specimens from the Chalamarca locality are slightly smaller than the holotype and vary in their dimensions, but otherwise show the colour pattern characteristic for this species, viz. corneous-brown with a whitish spiral band at the periphery of the last whorl.
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The shell is thin, narrowly umbilicate, conic, shaped like Lyogyrus brownii Carpenter. The color of the shell is slightly yellowish corneous. The shell is thin, smooth, with faint growth-lines. The shell has 4 whorls that are very convex and separated by deeply constricting sutures.
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The shell shows a fine lamellar sculpture. The circular aperture is feebly nacreous. The thick peristome is continuous and shows a callous varix. The multispiral operculum is hispid, corneous and has a soft, calcareous outer layer (intritacalx) formed of pearly beads that are disposed spirally.
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PDF . The name "trapdoor snail" refers the operculum, an oval corneous plate that most snails in this clade possess. When the soft parts of the snail are fully retracted, the operculum seals the aperture of the shell, providing some protection against drying out and predation.
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They are somewhat large sea snails - marine gastropod mollusks, with gills and a thin, circular, corneous, and many-whorled operculum. Their shell is conical with angular periphery. The spiral sculpture consists of raised cords, in many cases strongly beaded. The protoconch has a raised hexagonal pattern.
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They have a brown, entirely corneous, circular, multispiral operculum which fits the aperture snugly. The operculum is formed of numerous gradually increasing whorls with a central nucleus. The aperture may be entire, tetragonal or rounded and has no reflected lip. The peristome is generally not continuous.
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The operculum is ovate, thin, corneous and spiral, with polar point well forward and approximating the columella. The jaw is thin and membranaceous. The radula is odontophore, with teeth are arranged in transverse rows, according to the formula 3 + 1 + 3. Formula for denticles of rhachidian: .
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Its ocular peduncles and antennae are a solid orange and the antennal flagella are transparent. The corneous has parallel ridges on the palm, with similar ridges on the crabs' dactyls (the movable part of their pincers). The halloween hermit crab can live for up to 10 years.
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The base of the shell is flat, spirally, subobsoletely lirate. The aperture subhorizontal. The outer lip is thin, margined with brown or corneous. The columella is subhorizontal, curved, toothed below the middle, receding above, not spreading around the umbilicus as in some other species of this genus.
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Opercula are paucispiral and corneous, but may be vestigial in some species, not completely closing the aperture. The soft parts of the animal usually have a gray or brown coloration, commonly speckled with orange. The similar genus Juga has a seminal receptacle, but Pleurocera has no seminal receptacle.
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This arrangement is mainly based on morphological data, such as details of the operculum including the material (calcareous in the Naticinae, corneous in the Polinicinae and Sininae) and size, and also the morphology of the shell.Cernohorsky W.O. 1971. The family Naticidae (Mollusca: Gastropoda) in the Fiji Islands. Auckland Inst. Mus.
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The strong axial varices are often in two continuous series per whorl, one down each side of the shell. The nucleus of the corneous operculum is situated either at the anterior end or the mid-inner margin. A periostracum (hairy covering of the outer shell) is usually absent or thin.
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The horny operculum is composed of corneous material. The surface of the shell is smooth and shiny and lacks sculpture. Its color is a pale brown- yellow stained with orange to red-brown spots, arranged in four to five spiral lines. The shell of washed up specimens shows often a blue-black discoloration.
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The aperture shows at its base a vague curve or a distinct siphonal canal. The aperture is closed off by a thin oval brown operculum that is corneous and paucispiral. The palatal wall of the aperture is somewhat enlarged and often shows a varix. The taenioglossan radula has seven teeth in each row.
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The shell of this species is globular and can, under the right conditions, grow up to long. The operculum is large, ear- shaped in outline, and is corneous and somewhat transparent. On beaches where the shell of this species washed up commonly, the operculum will usually also be found washed up in the drift line.
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The inner spur taking the form of a hollow vesicle which is black inside, with an aperture near its base. The first two joints of tarsi bent, and produced outwards into a thin curved corneous (horn-like) wing, forming a shield overlying and protecting the modified spur, the terminal joint of tarsus and ungues very minute.
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The body whorl is obtusely angulated at the periphery. The sutures are scarcely impressed. The color of the upper surface grayish or corneous white, broadly longitudinally striped with red or purplish, the red sometimes covering the whole surface, sometimes reduced to small maculations or narrow lines. The base of the shell contains narrow zigzag radiating red stripes.
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The shell grows to a height of 7 mm. The shining shell is very small. It has a very narrow rim and is microscopically spirally striate. Its color is corneous with irregular spots of reddish brown, except immediately below the sutures, where they are replaced by a band of alternate oblique white, cream and reddish flammules.
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Stimpson (1865) described the genus as follows: “Shell ovate- conic, imperforate; apex acute; whorls coronated with spines; outer whorl nearly two-thirds the length of the shell; aperture ovate, outer lip acute. Operculum corneous, subspiral. Foot rather short for the length of the shell, broadest in front and strongly auriculated. Tentacles very long, slender, and tapering.
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Its upper margin is thin, slightly broken, but judging after the growth striae, sinuous above, protracted towards the keel, which appears to have been tooth-like. The basal margin is sinuous in the same manner;. The columellar margin is sinuous, reflected, and forms an angle with the basal margin. The operculum is very thin, corneous, with few whorls.
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It is little inflected above, excessively patulous on the base. The inner lip is thickened, extremely short, and slightly disunited from the body. It is very concave on the columella, where it is bent back so as to cover the umbilical perforation, which presents a narrowed and not pervious but very strong depression. The large, yellow operculum is corneous and thin.
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Asterivora combinatana by Des Helmore The larvae feed on Senecio bellidioides. They live in a silken gallery, which is formed amongst the young shoots of the plant. The larvae are somewhat stout and slightly tapering at each end. The head and dorsal surface of the prothorax are corneous and pale brown in colour, while the rest of the body is ochreous.
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The length of the shell of the shell attains 25 mm, its diameter 8 mm. The white, corneous shell has a turreted fusiform shape. It contains 11 whorls, The spiral lirations in this species are particularly prominent, especially upon the ribs, where in the body whorl they are developed into little nodules. The narrow, oval aperture measures about half the length of the shell.
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The height of the shell varies between 8 mm and 9 mm, its diameter between 9 mm and 11 mm. The small, conical shell is carinated and umbilicated. it is whitish or corneous, marked above with zigzag radiating stripes (sometimes broken into dots) of sepia or black, below unicolored white or sparsely dotted with black. The peripheral carina is ornamented with a series of black spots.
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These small snails are quite distinctive, because they have shells that are sinistral, which means that if you hold the shell such that the spire is pointing up, then the aperture is on the left-hand side. The shells of Aplexa species have a long and large aperture, a relatively high and pointed spire, and no operculum. The shells are thin and corneous and rather transparent.
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Historia Norwegiae was written sometime between 1160 and 1175 CE in an unknown location. It contains a list of peoples in the North: > But towards north many pagan tribes—alas!—stretch from the east behind > Norway, namely Karelians (Kiriali) and Kvens (Kwæni), corneous Sami people > (cornuti Finni) and both peoples of Bjarmia (utrique Biarmones). But what > tribes dwell behind them, have we no certainty.
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The about 10 whorls are quite planulate, or concave toward the upper, convex toward the lower margins. The body whorl is carinated at the periphery and flat beneath. The color of upper surface consists of longitudinal stripes or flames of brown, purplish, magenta, rose or coral red on a ground of white, corneous, pink or olive-tinted. The flames occupy more space than the ground color or vice versa.
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Shell of marine snail Lunella torquata with the calcareous operculum in place Gastropod shell of the freshwater snail Viviparus contectus with corneous operculum in place The operculum (plural: opercula or operculums), meaning little lid, is a corneous or calcareous anatomical structure like a trapdoor which exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape.
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Elimia virginica shells Elimia virginica belongs to the family Pleuroceridae, a group of snails that have thick, elongated shells. The operculum in this species is proteinaceous, corneous, and paucispiral and is withdrawn when the snail is active. The shells are dextral and have a very high and narrow spire, with little space in the suture (the incisions between the whorls). This species has two distinct shell morphologies, one smooth and one lirate (i.e.
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The height of the shell varies between 18 mm and 35 mm. The thin, light and acutely conical shell is imperforate. It is corneous or flesh-colored, more rarely rich orange, unicolored or sparsely articulated on the basal rilblets with rich brown, and frequently with rather obscure clouded niaculations of pale brown above. The surface is shining, closely sculptured by numerous narrow threads or riblets, which on the spire are contiguous, finely, regularly beaded.
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The shell is unique among Cerithioidea, because it has two deep sinuses: an anal sinus which is close to the suture and an anterior sinus more forward in the aperture. The height of the aperture is about one-fifth of the height of the shell. The height of the shell is usually 50–60 mm, but can be up to 90 mm. The operculum is oval, corneous and dark brown in color.
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The columella is smoothish to weakly ridged. The operculum is corneous and of variable thickness, with the nucleus near the anterior end or at about midlength of the outer margin. Many muricids have episodic growth, which means their shells grow in spurts, remaining the same size for a while (during which time the varix develops) before rapidly growing to the next size stage. The result is the series of above mentioned varices on each whorl.
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The peristome is broken, according to growth striae with a very shallow sinus below the suture. The columellar margin is concave above, directed to the left along the siphonal canal, with a thin layer of enamel. The operculum is thin, corneous, with a terminal nucleus at the left side. The radula shows 2 rows of teeth, in about 12 transverse rows, each tooth with a rather sharp point and a deep sinus at its basal margin, separating .
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The outer lip has a series of short, strong lirae, giving it a toothed appearance. The lower part of the inner lip near the siphonal notch has many "pimple-like" bumps or pustules. It has a yellow to brown corneous operculum, with an outline that matches the aperture's contour. The shell is colored pale tan or creamy white, sometimes purplish, with regularly-arranged, orange to light brown rectangular markings that often appear faded, even in fresh specimens.
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Melanophryniscus xanthostomus is a species of toads in the family Bufonidae, first found in the Atlantic Forest in Santa Catarina, Brazil. It is found at intermediate-high altitudes and has a phytotelm-breeding reproductive strategy. It is distinguished from its cogenerate species based on differences in snout-vent length; having white and/or yellow spots on its forearms, mouth, belly and cloaca; the pattern and arrangement of warts; and the presence and number of corneous spines. It might be threatened by habitat loss.
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Melanophryniscus milanoi is a species of toads in the family Bufonidae, first found in the Atlantic Forest in Santa Catarina, Brazil. It is found at intermediate-high altitudes and has a phytotelm-breeding reproductive strategy. It is distinguished from its cogenerate species based on differences in snout-vent length; having white and/or yellow spots on its forearms, mouth, belly and cloaca; the pattern and arrangement of warts; and the presence and number of corneous spines. It might be threatened by habitat loss.
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Melanophryniscus biancae is a species of toads in the family Bufonidae, first found in the Atlantic Forest in Santa Catarina, Brazil. It is found at intermediate-high altitudes and has a phytotelm-breeding reproductive strategy. It is distinguished from its cogenerate species based on differences in snout-vent length; having white and/or yellow spots on its forearms, mouth, belly and cloaca; the pattern and arrangement of warts; and the presence and number of corneous spines. It might be threatened by habitat loss.
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L. littorea is oviparous, reproducing annually with internal fertilization of egg capsules that are then shed directly into the sea, leading to a planktotrophic larval development time of four to seven weeks. Females lay 10,000 to 100,000 eggs contained in a corneous capsule from which pelagic larvae escape and eventually settle to the bottom. This species can breed year round depending on the local climate. Benson suggests that it reaches maturity at 10 mm and normally lives five to ten years.
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Adult specimens of Drymaeus inconspicuus can measure up to 25 mm shell height. The species is characterized by the corneous-brown upper whorls and the suture, which is bordered by a white line, descending slightly in front. Haas (1949) compared this species to Bulimulus transparens (Reeve, 1849), stating that his material was slightly smaller (17 vs. 19 mm shell height). The type material of Bulimulus transparens is in the Natural History Museum (BMNH 1975397) and is labelled ‘Venezuela’ (Breure, 1978: 147).
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Snails in the family Physidae have shells that are sinistral, which means that if the shell is held with the spire pointing up, and the aperture is facing the observer, the aperture is on the left-hand side. The shells of Physella species have a long and large aperture, a pointed spire, and no operculum. The shells are thin and corneous and rather transparent. Drawing of the eggs of Physella gyrina: upper image is the egg-mass showing position of eggs in envelope.
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As is the case in other volutes, the columella presents an array of strong oblique columellar folds (also known as plicae, 9 to 11 of them in this species), which are more conspicuous anteriorly.The corneous, claw-like operculum partially covers the shell aperture. Sexual dimorphism can be observed in the shells of this species: the shells of the males tend to be more elongate with a smoother outer surface, whereas the shells of the females are generally wider and more nodulose. The angle of the spire also differs between males and females.
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Most species of muricids are carnivorous, active predators that feed on other gastropods, bivalves, and barnacles. The access to the soft parts of the prey is typically obtained by boring a hole through the shell by means of a softening secretion and the scraping action of the radula. Because of their carnivory, some species may be considered pests because they can cause considerable destruction both in exploited natural beds of bivalves, and in farmed areas of commercial bivalves. Muricids lay eggs in protective, corneous capsules, the size and shape of which vary by species.
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The operculum of certain species of Turbinidae is sometimes used as a very inexpensive organic "gemstone" in rings, bracelets, amulets etc. These opercula are commonly known as "cats eye" (or more recently "Shiva's eye"). The turban snail Turbo petholatus is the species whose operculum is most widely used, although the operculum of other species of Turbo are sometimes used. The operculum is almost always given a solid setting, because it has one unattractive flat and corneous side where it was attached to the animal, and one roughly hemispherical glossy side, which, in the case of T. petholatus has a dark green area.
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The flared lip is absent in juveniles; it develops once the snail reaches reproductive age. The thicker the shell's flared lip is, the older the conch is. The external anatomy of the soft parts of A. gigas is similar to that of other snails in the family Strombidae; it has a long snout, two eyestalks with well-developed eyes, additional sensory tentacles, a strong foot and a corneous, sickle-shaped operculum. The shell and soft parts of living A. gigas serve as a home to several different kinds of commensal animals, including slipper snails, porcelain crabs and a specialized species of cardinalfish known as the conchfish (Astrapogon stellatus).
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The species has a large and powerful foot with brown spots and markings towards the edge, but is white nearer to the visceral hump that stays inside the shell and accommodates internal organs. The base of the anterior end of the foot has a distinct groove, which contains the opening of the pedal gland. Attached to the posterior end of the foot for about one third of its length is the dark brown, corneous, sickle-shaped operculum, which is reinforced by a distinct central rib. The base of the posterior two-thirds of the animal's foot is rounded; only the anterior third touches the ground during locomotion.
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The red pitahaya at the Chiyai market, Taiwan The flowers in Rome Dragonfruit stems are scandent (climbing habit), creeping, sprawling or clambering, and branch profusely. There can be 4–7 of them, between 5 and 10 m or longer, with joints from 30–120 cm or longer, and 10–12 cm thick; with generally three ribs; margins are corneous (horn-like) with age, and undulate. Areoles, that is, the small area bearing spines or hairs on a cactus, are 2 mm across with internodes 1–4 cm. Spines on the adult branches are 1–4 mm long, being acicular (needle-like) to almost conical, and grayish brown to black in colour and spreading, with a deep green epidermis. The scented, nocturnal flowers are 25–30 cm long, 15–17 cm wide with the pericarpel 2.5–5 cm long, about 2.5 cm thick, bracteoles ovate, acute, to 2.5 to less than 4 cm long; receptacle about 3 cm thick, bracteoles are linear-lanceolate, 3–8 cm long; outer tepals lanceolate-linear to linear, acuminate (tapering to a point), being 10–15 cm long, 10–15 mm wide and mucronate (ending in a short sharp point).
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