Hawaiian Marine Gastropods — OSTERGAARD 
93 
colored with corrugated distal margins. They 
were almost square and measured about 10 
mm. across (Fig. 13 a). 
Cleavage was not investigated in this spe- 
cies. After a period of 9 days the embryos 
had begun to show activity, short cilia having 
developed in three regions near the anterior 
end of the body. A shell had also begun to 
form, taking the form of a slipper, and begin- 
ning, apparently, at a dorsoposterior region 
of the body of the embryo, at which place it 
was attached (Fig. 13 b, c). As growth of 
the shell progressed, it spread to the side, 
becoming cup-shaped. This stage was ob- 
served 1 day later (Fig. 13^, e) . 
In the course of 24 hours an interesting 
transitional stage occurred. The lateral cili- 
ated areas constricted to form veliger lobes. 
The cilia grew rapidly and other cilia ap- 
peared along the borders of the lobes; the 
anterior cilia remained short, as did those 
now visible on the foot. The veliger lobes 
gradually unfolded and the embryo began to 
assume the appearance of the free-swimming 
form. The shell covered the greater part of 
its body. 
The embryo quickly grew into the free- 
swimming larva as the veliger lobes were 
completely unfolded and the cilia became 
capable of propelling the animal through the 
water. Since simultaneous development of 
the embryos in the capsule is not the rule, a 
provision seems to have been made for those 
that have been retarded in that the capsule 
does not expel its contents of young in favor 
of a minority, but remains closed until the 
great majority have reached the stage where 
the new environment becomes imperative. 
At the free-swimming stage the rather or- 
bicular veliger lobes were bordered with a 
row of pale-green pigmented cells; bristles 
projected from the tip of the ciliated foot, 
which was without an operculum and pointed. 
Eyes were present. The shell, measuring 0.28 
mm. in length, bore a fine granulation (Fig. 
13/, g). 
Fig. 13. Conus hebraeus Linnaeus, a, Egg cap- 
sules attached to rock; b, c, trochophore larvae 
showing beginning of shell formation after 9 days 
of incubation; d, e, trochophore stage after 10 days 
incubation; /, free-swimming veliger, ventral as- 
pect; g, free-swimming veliger, lateral aspect. 
Conus sumatrensis Hwass 
Fig. 14 
May 16, 1921, while collecting about 50 
meters off the Marine Laboratory, I found a 
group of 34 egg cases of Conus attached to 
the lower side of a piece of coral, and right 
beside them was a Conus sumatrensis. Inas- 
much as the zygotes were in very early stages 
of cleavage, there could be little doubt as 
to their identification. 
The egg cases, quite unlike those of other 
known species of Conus described in this 
paper, are very soft and thin; they average 
