Fig. 122 B is a diagrammatic representation of the adult eye of a gasteropod.
One of the lowest forms of tongues is that of the gasteropod.
The growth of nearly all gasteropod shells is marked by periods of rest.
A good knowledge of the parts of a gasteropod shell is essential to the student, and it can readily be acquired.
Beautiful pink pearls are found in the gasteropod Strombus gigas, the conch-shell of the West Indies.
gasteropod shells may be sinistral or dextral, according as the whorls turn to the left or right.
In almost all gasteropod and Pteropod larv there is present a well-developed spindle muscle attaching the embryo to the shell.
This is a very curious creature when considered from the point of view of the gasteropod mollusk.
We can tell you even the precise kind—it is the gasteropod kind.
It is apparently the only gasteropod that lives in the open sea and has a large and well-formed spiral shell.