120 
PACIFIC SCIENCE, Vol. IX, April, 1955 
Fig. 7. Pleurobranchus delicatus (Pease), dorsal, ven- 
tral, and lateral aspects (natural size); branchial plume 
(enlarged). 
found on windward Oahu, near Makapuu, 
June 30, 1950. 
The specimen I have figured (the first one 
obtained) has a much smaller cloak than 
others (obtained later) which agree with 
Pease’s description. It is possible that the 
cloak might have been injured and was in 
process of regeneration. 
Placobranchus ianthobapsus Gould 
Fig. 8 
Placobranchus ianthobapsus Gould, U. S. Expl. 
Exped. 12: 307, pi. 26, figs. 407a-c, 1852. 
Body elongate, dorsoventrally compressed, 
tapered slightly toward truncate posterior ex- 
tremity. Oral hood broad, lateral continua- 
tions of which form the tentacles. Mouth 
situated ventrally, within cavity formed by 
hood. Tentacles involute, retractile apically, 
tapering distally, directed laterad at base and 
distal ends usually turned slightly upward and 
forward, much like the horns of an ox. They 
are whitish yellow to vivid greenish yellow, 
with tips of pale reddish purple that tends 
to form a band of a deeper tinge. Dorsal 
surface light yellowish green to pale green, 
in some specimens clouded with olive green 
or olive brown. Ocelli crowding surface of 
head and body, of three types: (1) small, 
numerous bodies with yellow or brownish- 
orange pupil surrounded by a white iris; (2) 
a larger and less numerous type with yellow- 
ish or olive-green pupil with light-green cen- 
ter and white iris surrounding pupil; (3) the 
largest type and least numerous, with greenish 
or sky-blue pupil surrounded by a thick black 
ring and usually without the white iris. These 
ocelli are usually promiscuously scattered and 
intergrade with one another; but in some 
individuals they tend to become arranged bi- 
laterally on the dorsal surface, especially the 
large black-ringed type, which are always nu- 
merous along the lateral margin of the foot. 
Eyes small, retractile, placed in shallow orbits 
on lateral sides of an anteriorly pointing 
prominence on the middorsal side of head. 
Branchial surface pale green with numerous 
longitudinal folds crowded with grass-green 
algae. Cardiac swelling triangular, white and 
prominent, placed directly posterior to the 
head. Margins of the body, meeting mid- 
dorsally, thick, pellucid, whitish blue with a 
series of opaque yellowish -green oval or ob- 
long bodies. Foot bluish green with numerous 
ocelli of unequal sizes with pupils from olive 
