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PACIFIC SCIENCE, Vol. XV, April 1961 
stage, with the four macromeres and many mi- 
cromeres distinctly visible. It is likely that the 
embryos were 1-2 days old. They were oval in 
shape, measured 175-200 X 165-175 g, and 
were slowly motile when released from the cap- 
sule into sea water. The blastula is the earliest 
stage at which activity is observed in Conus 
embryos (Ostergaard, 1950). 
An egg capsule opened on the second day 
after collection contained motile embryos which 
resembled early trochophores (Fig. 'ba) . The 
resemblance of this stage to typical trochophore 
larvae is somewhat closer in C. abbreviatus than 
in other species of Conus (see below and Oster- 
gaard, 1950) in which the trochophore stage 
is suppressed. This is typical of gastropods in 
which this stage is passed within an egg capsule 
or brood pouch (Raven, 1958)'. 
The trochophore-like embryos of C. abbrevi- 
atus measured 270 X 170 g and retained the 
pink color of the previous stage. On the fourth 
day after collection, the first traces of shell were 
visible (Fig. 3 b). Two days later, velar lobes 
were beginning to form (Fig. 3 c) and the em- 
bryos, which now measured 255 X 150-165 g, 
swam actively when released from the capsule. 
On the 9th day after collection the velar lobes 
and larval shell appeared to be fully developed 
(Fig. 3 d—f). The pink color persisted, and the 
shells were transparent and bore numerous fine 
nodules (Fig. 3 d, e ) . Otocysts, eyes, heart, foot, 
and operculum were easily visible. The maxi- 
mum dimension of the shell was 270 g, and the 
breadth of the velar lobes was about 250 g. The 
veligers were motile within the capsule and 
swam actively when released from it into sea 
water. No further development was detected on 
the 11th day after collection. On the 13th day 
after collection, presumably the 14th or 15th 
day after oviposition, some veligers hatched 
from egg capsules following apparent dissolu- 
tion of the exit window. The hatched veliger 
larvae closely resembled those in Figure 3 d—f 
but measured 275-300 /x in maximum shell 
dimension. They swam freely in the container 
and were colorless except for a row of green 
pigment spots inside the margins of the velar 
lobes (Fig. be, /). Unhatched veligers within 
the capsule retained the pink color in the vis- 
ceral mass. 
Fig. 2a. Egg capsules of Conus abbreviatus Reeve. 
Diamond Head, Oahu, 10 March 1956. Portion of a 
row of capsules affixed to metal can lid. 
Within two days the rest of the veligers ap- 
peared to have hatched from the capsules. Dur- 
ing the ensuing 10 days no further development 
was observed and none of the larvae settled to 
the bottom of the container to assume the 
benthic mode of life. By the 11th day after 
hatching, all of the larvae were dead and the 
observations were terminated. The course of 
larval development is summarized and compared 
with that of other species in Table 3. 
Conus catus Fiwass in Bruguiere 
A specimen of C. catus (no. 2180) collected 
at Lower Paia, Maui, on 5 August 1956, was 
observed to have affixed a single egg capsule 
to its shell about 2 hr. after collection. The 
capsule measured 12 X 10 mm. 
On 22 August 1956, a female C. catus (no. 
