Hawaiian Marine Gastropods — OSTERGAARD 
body. The veliger lobes had also attained a 
large size, yet the cilia bordering them re- 
mained short. The heart could be seen dis- 
tinctly as a single-chambered oval bag on the 
dorsal side posterior to the veliger lobes. Its 
alternate contraction and expansion would 
change its volume about 100 per cent. The 
large veliger lobes were bordered by a single 
row of yellowish pigment cells, A pair of 
blunt papilla-like tentacles supporting the 
eye were tipped with a few short bristles. 
The shell showed a fine granulation. No 
operculum was present on the large foot 
(Fig. lid). 
At the 1 sixteenth day of incubation some 
changes were noticeable. The two veliger 
lobes had developed greatly, each having a 
deep lateral indentation. The cilia also had 
increased greatly in size and were beating 
rhythmically, keeping the animal upright 
with the apex of the shell against the bottom. 
The large bilobed foot supported a small 
operculum on one of its lobes and was cov- 
ered with very fine cilia; a few prominent 
bristles were present at its opercular end. Two 
prominent tentacles, bearing the eyes on basal 
swellings and beset at their extremities with 
a large tuft of bristles, occupied a central 
position on the veliger lobes (Fig. 1 le). 
At this stage, 1.6 days of incubation after 
the beginning of cleavage, the larvae began 
to escape into the water, but, unlike those of 
other species here observed, they remained 
within the albuminous substance of the cap- 
sule which had been discharged into the wa- 
ter and did not attain the power of swimming 
at any time while under observation. This 
inability to swim may be ascribed to the great 
size and weight of the shell, some of the veli- 
ger shells having attained a length of over 
1.25 mm. with about one and a half volu- 
tions (Fig. Ilf, g). A fine granulation cov- 
ered its entire outer surface, which had taken 
on a faint golden tinge, most pronounced 
anteriorly. The columella seen through the 
quite transparent shell had a pale rose tinge. 
91 
This coloration of the veliger shell is an ap- 
proach to that in the shell of the adult. 
Egg capsules corresponding to those of 
Conus omaria were found near the Marine 
Laboratory, May 25, 1922, but were of a 
larger size than the first lot. These capsules 
contained advanced veligers, one capsule 
containing about 40, another as many as 150 
embryos. Some of the larvae of this lot were 
kept for over a week after their escape from 
their capsule without ever showing signs of 
swimming. Some, however, would drag their 
shells on the bottom of the dish by means of 
the propelling force of their velar cilia. A 
number of the larvae were normally expelled 
from the capsule, which seemed to be effected 
by a dissolution of the "window” at the free, 
or distal, end of the capsule, followed by a 
contraction of the capsular walls, resulting in 
a squeezing out into the water of the albu- 
minous substance containing the larvae. It 
may be that both chemical and mechanical 
agents are responsible for this occurrence, 
and that the larvae, at the time of their lib- 
eration, emit some secretion which brings 
about the desired results. 
A circumstance which might be correlated 
with the absence of a free-swimming stage of 
this species is the fact that Conus omaria oc- 
curs in many varietal forms in various parts 
of the Hawaiian Islands; so much so that 
some authorities are inclined to consider some 
of them distinct species. 
One might suppose that the free access to 
widespread areas possessed by those species 
having such an efficient mode of dispersal as 
a pelagic veliger larva would serve to break 
down varietal strains which might be in pro- 
cess of development and thus tend to stabilize 
the species, whereas an immotile larva, as 
here observed in Conus omaria, would have 
the opposite effect. 
Conus catus Hwass 
Fig. 12 
On June 12, 1922, a mass of egg capsules 
