MORSE: OBSERVATIONS ON LAMELLIBRANCHS. 
145 
were made to ascertain the form of the protoconch; the hcakfi 
of the shells, however, were too eroded to admit of making out 
any feature of the early stages. Through the kindness of Mrs. 
Clapp I had the privilege of examining some very youngspecimens 
and among these I found the long-sought protoconch. The 
specimen in which the outline was perfectly clear was not over a 
millimeter in length and the protoconch was about the twentieth 
of a miUimeter. The interesting discovery was made that the 
protoconch instead of being orbicular, or nearly so, as in most 
lamellibranchs, was markedly oblong as shown in Fig. 1, a. The 
FiQ. 1. — Solemya telum Say. 
outline was not unlike that of an adult Machaera. The succes- 
sive stages as indicated by the lines of growth were quite different 
from the outline of the adult. The straight hinge line was con- 
tinued behind the beaks instead of rounding ofif as in the later 
stages. Realizing the primitive character of Solemya as shown 
by Pelseneer, it will be a matter of extreme interest to secure 
observations on the embryology- of this genus. 
Solemya lives buried in the mud and contrary to all burro^wing 
lamellibranchs buries itself head downward. It apparently lives 
in definite burrows which it constructs, or it may occupy aban- 
doned wormholes. It has a long, powerful, muscular foot capable 
