Hawaiian Marine Gastropods — OSTERGAARD 
duced laterally into two angular processes, 
and anteriorly, as in M. astricta, into a blunt, 
rounded process with bristles. Eyes and oto- 
cysts were present. The marginal bands on 
the velum were greenish-brown. Numerous 
spots of the same color occurred also on the 
foot. The length of the shell was 0.25 mm. 
(Fig. 9c— f). The larvae showed a strong 
positive phototropism. 
Family CON1DAE 
Genus Conus 
Conus tahitensis rattus Hwass 
Fig. 10 
While collecting on the outer reef near 
the Elk’s Club at Waikiki during the morn- 
ing of August 4, 1921, I picked up a speci- 
men of Conus tahitensis in the act of deposit- 
ing eggs. I broke off the rock to which the 
egg capsules were attached and took it to the 
laboratory. 
There were 22 egg cases of a soft, thin 
structure and of a comparatively large size, 
about 11x15 mm. Each egg case contained 
about 2,000 ova of rather small size, 0.125 
mm. (Fig. 10a) . 
The ova, in respect to distribution of yolk 
(deutoplasm) and cytoplasm, agreed closely, 
insofar as could be observed without spe- 
cial preparations, with those of Cypraea and 
Mitra. 
The early stages of cleavage were observed 
in a capsule about 6 hours after deposition 
The first division resulted in two cells of 
equal size. These rounded out independently 
until the two cells were joined to each other 
by a very small area. Soon they contracted 
toward each other to assume the appearance 
they had before the first division was com- 
plete (Fig. 10b, c, d ). The second division, 
resulting in four cells of equal size, had oc- 
curred about 1 hour after the first. Here 
again, as in the first division, the cells were 
rounded off and standing out prominently. 
89 
0 I mm. 
Fig. 10. Conus tahitensis rattus Hwass. a, Egg 
capsules attached to rock; b-k, cleavage stages from 
the ovum to the blastula stage. 
These again became pulled toward the cen- 
ter, so that the entire mass became neatly 
spherical (Fig. lO^, /). The next cleavage 
was unequal, resulting in four micromeres 
and four macromeres, as in Cypraea and 
Mitra (Fig. lOg) . Succeeding cleavages re- 
sulted in a cap of micromeres at the animal 
pole. The macromeres now divided nearly 
equally into four cells of lesser size which 
came to lie at the equator, and four larger 
ones which surrounded the vegetal pole. The 
micromeres soon extended to the equator, 
covering half of the sphere of the embryo 
and projecting out beyond the macromeres 
(Fig. 10 h, i, j). 
This was the blastula stage and the em- 
bryo now began to show activity. It appeared 
that in some of the embryos another division 
of the four equatorial macromeres had taken 
place, as some embryos had 12 macromeres 
