Hawaiian Marine Gastropods — OSTERGAARD 
97 
yellow color was seen in the animal’s visceral 
mass. The shell, measuring 0.55 mm. in 
length, was covered with a fine reticulum of 
slightly elevated polygonal areas (Fig. 19c). 
It was tinged with carmine along the margin. 
It is of interest to compare the egg struc- 
ture and larva of this species with those of 
one recorded from the Iranian Gulf by Gun- 
nar Thorson (1940: 192-195). 
Family L1TT ORIN1DAE 
Genus Littorina 
Littorina pintado Wood 
Fig. 20 
A large quantity of eggs was obtained 
from a number of specimens of Littorina 
pintado which were kept in a glass of water 
in the laboratory. The eggs were deposited 
during the night and in the morning were 
found scattered in profusion over the bottom 
of the glass. 
Each ovum, contained within a hyaline 
membrane, was usually enclosed in a capsule 
alone; rarely two or more ova were present. 
The capsules were somewhat globular or pyri- 
form, flat on one surface and convex on the 
other with a transverse diameter of the flat 
Fig. 19. Tonna ( = Dolium) perdix ( Linnaeus ) . 
a, Egg structure; b, egg envelopes with grouped 
masses of ova; c, free-swimming veliger larva 
showing a prominent proboscis. 
and numerous micromeres, the latter reach- 
ing about to the equator. A day or two later 
a stage in which the embryos showed a 
slight amount of movement was attained. 
This was probably the blastula stage, the seg- 
mentation cavity being occupied by the large 
macromeres. 
The length of time required for the larva 
to become a free-swimming veliger was not 
recorded. At this stage the larva was pro- 
vided with large veliger lobes, eyes, a long 
proboscis, and a rounded foot with an oper- 
culum extending beyond its borders. A pale- 
Fig. 20. Littorina pintado Wood, a, Egg cap- 
sules enlarged; b, c, egg capsule magnified, and 
seen from edge and flat surface. 
