174 
PACIFIC SCIENCE, VoL XV, April 1961 
Fig. 11. Portion of a row of egg capsules of Conus 
quercinus Solander. Sand Island, Kaneohe Bay, Oahu, 
9 February 1956. 
cluster extends upward into the water and is 
not covered, it soon becomes a substratum for 
epiflora and epifauna. The characteristics of the 
egg masses of C. quercinus are summarized in 
Tables 1 and 2. 
On the day of collection, one capsule was 
removed from the large cluster and found to 
contain pale pink, uncleaved, round-to-ovate eggs 
embedded in albuminous material and measur- 
ing 175-250 g (Fig. 12 a). The egg mass had 
probably been deposited on the same day. On 
the following day the first cleavage furrow was 
visible (Fig. 12b). On the 3rd day after collec- 
tion, it was difficult to discern cell outlines, but 
the embryos, which were now white, appeared 
to be in the second to fourth divisions (Fig. 
12 c, d) and were motile when released from 
the capsule into sea water. Another capsule 
examined on the 5 th day after collection showed 
little further progress. The embryos were quite 
motile and micromeres were observed in a few. 
Two days later, the embryos had increased in 
size to 240 X 180 g and were in the modified 
trochophore stage (Fig. 12e). 
Two days later, on the 9th day after oviposi- 
tion, the embryos had grown to a maximum size 
of 315 X 195 g and the shell and velar lobes 
had begun to form (Fig. 12/). Two days later, 
the fully developed veliger shells had attained 
a length of 255-295 The velar lobes were well 
developed, and the heart, kidney (which was 
bright red), otocysts, eyes, and mouth (which 
measured 6 X 23 g) were visible (Fig. 12 g, 
h , i). The small foot rudiment bore a large 
operculum. The shell was brown and decorated 
with many rows of brown nodules, which were 
about 3 g in diameter, rose 3-4 g above the 
surface of the shell, and were about 3 g apart. 
The growing lip of the shell was transparent. 
On the 13 th day after oviposition, the veligers 
were motile within the capsules and in many 
they were crowded in the vicinity of the exit 
window. Veligers removed from one capsule 
were found to have a row of green pigment 
spots, about 1 5 g in diameter, inside the margins 
of the velar lobes, which had grown to about 
285 g across. The shells had not increased in 
size, but the outer lip was no longer transparent, 
indicating increased thickness. Two days later, 
on the 15 th day after oviposition, some veligers 
hatched from the capsules and were swimming 
actively about in the container. By the following 
day most, and on the next day all, of the cap- 
sules had hatched. 
Although the foot increased in size during the 
next few days, no significant over-all growth was 
apparent, and the velar lobes of some hatched 
veligers appeared reduced in size (Fig. 12/). 
None of the larvae settled to crawl on the bot- 
tom. Mortality in the culture gradually increased 
and only one or two larvae remained alive on 
the 8th day after the first hatching, when the 
observations were terminated. 
Conus rattus Hwass in Bruguiere (?) 
A cluster of 31 egg capsules was collected 
from depressions in the underside of a large 
coral rock in 1 m. of water on the reef opposite 
the marine laboratory at Waikiki, Oahu, on 21 
March 1956. No adult Conus was present in the 
immediate vicinity, but the capsules closely re- 
semble those of C. rattus described by Oster- 
gaard ( 1950) . 4 They are tentatively assigned to 
that species, which is not uncommon on the 
same reef. 
The capsules (Fig. 13) measured 11-15 X 
10-14 mm. and most were empty. However, a 
few contained veliger larvae, which hatched soon 
after being placed in a vessel of sea water in 
the laboratory. The veliger shells were yellowish 
brown with darker brown granulations and 
measured 240 g in maximum dimension. Eyes 
and otocysts were visible and a row of green 
pigment spots was present around the margins 
of the velar lobe. A few of the larvae remained 
4 This species is referred to as C. tahitensis rattus 
Hwass by Ostergaard (1950). 
