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PACIFIC SCIENCE, Vol. XV, April 1961 
found to contain eggs in 1-, 2-, and 4-cell stages; 
the last measured about 250 /x across. On the 
second day after collection, a capsule contained 
embryos which still measured 250 /x in diameter 
but had progressed to the blastula stage. The 
observations had to be terminated at this point, 
but development thus far was essentially similar 
to that in the egg mass described above. 
DISCUSSION 
Fig. 13. Views of an egg capsule tentatively as- 
signed to Conus rattus Hwass in Bruguiere. Waikiki, 
Oahu, 21 March 1956. 
(Fig. 15a, b ) . Oviposition probably occurred 
earlier the same day. Two days later, the embryos 
had progressed to the early blastula stage and 
macromeres and micromeres were distinctly vis- 
ible (Fig. 15c). A capsule examined on the 6th 
day after collection was found to contain motile 
trochophor e-like larvae which measured 360 X 
210 fx (Fig. 15 d) . On the 9 th day, the veliger 
stage was fully developed, the maximum dimen- 
sion being 375-^00 /x (Fig. 15 e, /). On the 
11th day, the veligers were motile within the 
capsules and on the following day crowding 
toward the exit window was observed. All of the 
capsules hatched during the next 3 days, or 14- 
lb days after oviposition. The otocysts and red- 
dish-brown kidney were visible and green pig- 
ment spots almost filled the velar lobes of some 
individuals. 
Some of the veligers swam about freely in 
the vessel, but most remained on the bottom, 
which had been covered with sand from the 
reef, and propelled themselves by beating the 
velar cilia. When disturbed, they swam briefly 
away from the source of irritation. However, 
none of the larvae settled to crawl on their feet, 
and all had died without undergoing any further 
growth or development by the 4th day after 
hatching began. 
On 24 July 1957, a cluster of 12 egg capsules 
was found attached to the underside of a coral 
rock in a large tide pool at Diamond Head, 
Oahu. A large adult C. vitulinus (no. 7034, 65 
X 37 mm., sex undet.) was present on the sand 
substratum under the rock. Upon return to the 
laboratory, one of the capsules was examined and 
Spawning site and season . Egg capsules of 
Conus have been collected on 31 known occa- 
sions in Hawaii, chiefly by Ostergaard (1950) 
and by the writer and colleagues. All collection 
records are summarized in Table 1. At least 12 
species are represented. 
As noted previously (Kohn, 1959 b ) : 
Coral reef platforms, but not marine ‘benches, 
provide suitable attachment sites for egg cap- 
sules of Conus. Of 36 egg masses collected in 
the field, 29 were recorded from reef platforms. 
An almost complete absence of records from 
marine benches suggests that spawning is un- 
successful there. This is probably due to the 
absence of protected pools in which egg cap- 
sules may be deposited without being subject 
to desiccation at low tide and/or torn away by 
heavy surf at high tide. Recruitment of bench 
populations [of adults} is probably from pelagic 
veliger larvae which have been carried from 
other areas and are washed onto marine benches 
in condition to settle and assume the benthic 
mode of life. 
All of the capsules were collected between 
February and August, although search for them 
was not restricted to, or emphasized during, that 
period. The data suggest that most species of 
I cm 
Fig. 1 4. Views of an egg capsule of Conus vitulinus 
Hwass in Bruguiere. Ala Moana, Oahu, 7 July 1956. 
