90 
PACIFIC SCIENCE, Vol. IV, April, 1950 
This was also observed in Cypraea carneola 
and is probably a common condition (Fig. 
10£). Owing to the loss of all the larvae, 
no further observations on the development 
were made. 
In February, 1923, another Conus tahi- 
tensis with egg capsules was found near the 
laboratory. The egg capsules were much 
smaller, but agreed in other respects with the 
one described, i.e., in color, texture, number, 
and size of ova. As in the previous lot none 
developed beyond the blastula stage. 
Conus omaria Hwass 
Fig. 11 
On May 19, 1921, I found, near the labo- 
ratory, a number of Conus egg cases which 
were attached to the underside of a rock. 
Under this rock also was an adult Conus 
omaria, a rather rare species on this reef. The 
egg capsules differed from all those previ- 
ously observed in that only a few of them 
were attached directly to the rock; the greater 
number, about 34 in all, were joined to one 
another, forming arches and bridges (Fig. 
11a). 
Upon examining the contents of one of 
these capsules, I found zygotes in very early 
cleavage stages. Some were still unsegmented, 
while a number were in the two-cell stage, 
the result of an equal division. A few had 
undergone a second division which was equal, 
four blastomeres of a smaller size resulting. 
The capsules of this species, measuring 
about 1 1 mm. in length and 8 mm. in width, 
contained a small number of large ova, 0.47 
mm. in diameter, often less than 50 in one 
capsule. The zygotes failed to develop when 
removed from the capsule,, so it was neces- 
sary to open one each day to follow their 
progressive development. Five days after they 
were obtained some of the embryos had be- 
gun to form a shell. And after 11 days of 
incubation they had attained well-advanced 
stages, a large shell having formed about the 
Fig. 11. Conus omaria Hwass. a, Egg capsules 
attached to rock; h—d, stages of development in 
veliger larva, heart showing as a globular body 
in d\ e, veliger larva after normal release from 
capsule; f, g, shell of veliger larva. 
