Biology of Conus , I— Kohn 
171 
Fig. 5. Views of an egg capsule of Conus imperialis 
Linnaeus. Diamond Head, Oahu, 6 July 1956. 
two or more weeks prior to their collection, it 
is by no means certain that the adult female 
associated with them was the parent. Indeed, it 
is not certain that the capsules are actually those 
of C. lividus , and the identification is tentative. 
It is supported, however, by morphological sim- 
ilarities with capsules known to have been de- 
posited by C. lividus in other areas (Kohn, ms) . 
The capsules are distinguished from those of 
several other species of Conus by being some- 
what more discoid in form and bearing crena- 
tions along the edges of the otherwise rather 
smooth capsular wall (Fig. 7). There are also 
two more or less parallel ridges extending down- 
ward from the corners of the exit window, as 
in C. abbreviatus . The capsules in the smaller 
group, shown in Figure 7, averaged 11 mm. in 
height and maximum breadth. The capsules in 
the other group were essentially similar in ap- 
pearance but were slightly smaller, averaging 
9.5 mm. in both dimensions. 
The veliger shells, 235-260 \x in maximum 
dimension, were yellowish brown and bore 
minute densely-packed, raised, darker brown 
nodules over the entire surface. 
Conus pennaceus Born 
Egg masses of C. pennaceus have been col- 
lected on numerous occasions in Hawaii (Table 
1). As noted by Ostergaard (1950) the egg mass 
of C. pennaceus 3 differs from those of other 
species in that only a few capsules are attached 
directly to the substratum. Most are affixed to 
previously deposited capsules, thus forming the 
:5 This species is referred to as C. omaria Hwass by 
Ostergaard (1950). 
"arches and bridges” mentioned by Ostergaard 
and making the entire mass very compact ( Fig. 
8). The individual capsules are typical of the 
genus (Fig. 9). 
In the present study, 10 egg masses of C. 
pennaceus were collected on seven occasions, all 
in the months of June, July, and August (Table 
1). The 2 egg masses reported by Ostergaard 
(1950) 3 were collected in May. The data sug- 
gest May-August as the breeding season of this 
species. 
The development of C. pennaceus from fer- 
tilized egg to hatching has been described and 
illustrated by Ostergaard (1950). It was pos- 
sible to follow portions of the course of larval 
development in 2 of the egg masses listed in 
Table 1. 
On the day after collection, the egg mass frotn 
Diamond Head, Oahu, 10 June 1956 (which 
was found adrift over the reef by P. Helfrich), 
contained early veliger larvae which appeared 
to be in the later stages of torsion. A very small 
shell rudiment, a slowly beating heart, and eyes 
were present. On the 4th day after collection, 
the veligers appeared to be between the stages 
shown by Ostergaard s figures lid and lie, or 
probably about 12-13 days from oviposition. 
The siphonal canal of the shell had begun to 
form, and a row of chartreuse pigment spots 
was present along the margin of the velar lobes. 
During the next 7 days, the shells gradually 
grew to 1.1 X 0.7 mm., and the wall of the exit 
window became thinner and more transparent, 
but no capsules hatched. Hatching of a few cap- 
sules finally occurred on the 16th day after col- 
lection. This probably corresponded to 25-26 
Fig. 6. Egg capsules of Conus leopardus (Roding). 
Kaneohe Bay, Oahu, 25 April 1956. a, Side view of 
one capsule; b and c, opposite side and edge views of 
another capsule. 
