7 
number of ocelli. The larger size of the body may play a part in 
this condition. The brain is clearly bi-lobed (text-fig. 5, and Plate 
I, Fig. 7), while in C. colobocentroti it is nearly rounded. 
The pharynx is relatively longer and narrower (Plate I, Fig. 9), 
and the mouth even further back (compare Plate I, Fig. 6, where 
the pharynx is partly pro- 
truded through the mouth) 
than in the Krakatau-spe- 
cimens. The postoral part 
of the pharyngeal pocket 
constitutes only Vio of its 
total length. The male 
genital apparatus is set far 
apart from the pharyngeal 
pocket (text-fig. 4), contrary 
to that in colobocentroti. 
The hinder commissure of 
the seminal canals is fur¬ 
ther away from the female 
gonopore (text-fig. 7). 
However, we find the 
real difference in the female 
genital apparatus. All the 
Hawaiian specimens agree 
in the ductus vaginalis 
being considerably length- ArrangeSfo? 
ened and possessing a long 
^oop frontwards in direction 
lowards the male organ (text-fig. 7). 
The descriptions given above doubtlessly show that it is not 
unwarranted to regard the Cera^op/ana-specimens from Hawaii 
as at least a special variety, as long as transitory forms are unknown. 
Hence, the reason I am letting the Cera/op/a/za-specimens from 
the Sunda Straits represent the species is based on the faet 
that I consider the elongation of the ductus vaginalis as a second- 
arily acquired feature. 
The three least contracted specimens from Hawaii are repro- 
■duced in fig. 2—9 on the Plate. The largest specimen measures 
14 mm. in total length and 6 mm. in breadth, in the pharyngeal zone. 
Text-fig. 5. 
Ceratoplana colobocentroti var. haivaiiensis. 
gement of cerebral and tentacular eyes. 45 x, 
ph. pharynx; i, anterior unpaired intestinal 
diverticulum. 
