Examples from the Web for shell gland
The shell-gland becomes fully developed opening at the base of the first pair of maxill.
In A the shell-gland and the mouth and the rudiment of the enteron are shown; primitive mesoderm cells.
This pit, which has already been spoken of as the shell-gland, resembles very closely the shell-gland of other Mollusca.
In B the shell-gland has flattened out and the shell is formed.
Its cells first become differentiated into mesoblast and hypoblast after the shell-gland has become a fairly deep pit.