Another association is that of a gasteropod with one of the acephala.
It is evidently a gasteropod mollusc, allied to the Natices, and lives in the interior of the body of a Synapta, but we do not yet know all the phases of its 159 evolution.
This crab is known by the name of Pisa Styx, the gasteropod is a Cypraea, the polyp is the Melithea ochracea.
A crab of the family of the Maidae conceals itself in the substance of a polypidom very common in the Viti Islands, in company with a gasteropod mollusc, and both of them assume the exact colour of the polypidom.
This animal, as is well known, adopts an empty whelk-shell or other gasteropod shell as its own.
A very peculiar modification of the ordinary Gasteropod segmentation is that described by Bobretzky for Nassa mutabilis[44].
The byssus-gland occupies very much the position of the Gasteropod operculum, and would appear very probably to correspond with this organ.
In all Gasteropod Molluscs the lower or vegetative pole of the ovum is ventral, not dorsal as Rabl would make it in Unio.
In almost all Gasteropod and Pteropod larvae there is present a well-developed spindle muscle attaching the embryo to the shell.
In Cephalopods the position of the Gasteropod foot is occupied by the external yolk-sack.
It may be noted that from the third stage onwards the cells increase in arithmetical progression--a characteristic feature of the typical gasteropod segmentation.
The segmentation takes place according to the most usual Gasteropod type; (vide p.
Turbinella, a genus of Gasteropod molluscs, natives of the East Indian seas, used as ornaments by Hindu women.
They are crowded with pteropod shells, and contain also small gasteropod and lamellibranchiate shells together with tests of foraminifera both microscopic and macroscopic.
This is a shallow-water deposit and contains, besides small gasteropod shells, large flat tests of foraminifera 5 or 6 mm.
The gasteropod shell therefore grows by the continual building out of its aperture through successive depositions of shelly matter at the extreme edge of the lip.
A minute calcareous tube, in a close, flat coil attached on one side; easily mistaken for a minute gasteropod shell; worm has an operculum and wreath of gills.
Let us now take a good example of a gasteropod and locate its various organs; at the same time we may use the occasion to refer to more important modifications of these organs which will be encountered later in the various genera.
The foot is also large, and by its disk-like surface is adapted to creeping, much as is a gasteropod foot; its edges are often crenulated or scalloped, and there is no trace of a byssus.
The organization of a pelecypod is entirely similar to that of a gasteropod or a chiton in its fundamental or essential plan, but it differs widely from both in matters of detail.
The mantle portion covering the visceral hump naturally continued to secrete its shell, though always in conformity with the change, the result being the familiar spiral form of the usual gasteropod shell.
The usual gasteropod shell is in reality a hollow tube wound about an imaginary axis.
This is said to be the largest gasteropod shell known.
The growth of nearly allgasteropod shells is marked by periods of rest.
The shell, in consequence, having almost ceased to be of use as a protection, has degenerated into a mere horny plate, and has lost all resemblance to the ordinary gasteropod shell.
If a living gasteropod is placed in a jar of sea-water and left undisturbed it will soon crawl up the side of the glass and thus afford an excellent view of the extended under surface of its foot.
The long stretches of sand are everywhere rich with perhaps the most beautiful shell in the world, that giant gasteropod technically called Strombus but commonly known as fountain-shell.
Gasteropod shell, Murex ramosus, the Branchy Murex, aptly enough named from the many prickly branches which beset it.
D] There are one or two exceptional cases of gasteropod molluscs that have no tongue-ribbon.
Whelks and other Gasteropod Molluscs, which they carry about with them as portable shelters.
This unsymmetrical development of the appendages is interesting as indicating the derivation of the Robber Crab from ancestors adapted to living in the unsymmetrical shells of Gasteropod Molluscs.
Hermit Crabs in general shape, and like them use the shells of Gasteropod Molluscs as portable shelters.
Whorl#, a single coil in the spire of a gasteropod shell.
Distribution, throughout the tropical, and warmer temperate seas of the whole world; attached to turtles, crustacea, or smooth gasteropod molluscs.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "gasteropod" in a variety of sentences. We hope that you will now be able to make sentences using this word.
