130 H. J. HANSEN. 
apparently not recognised by any zoologist since it was 
established in 1840. Among numerous marine animals from 
Akaroa Harbour, New Zealand, I found several specimens of 
a species of Cassidina, determined it as C. neo-zealanica 
(Thoms.), examined its structure, and worked out a set of 
analytical figures. When I, more than a year after, studied 
the literature on Spheromide and looked on the figures given 
by Milne-Edwards in 1840, I was struck by the similarity as 
to certain points between these and my own drawings. I 
was speedily convinced that C. neo-zealanica must be either 
a species closely allied to C. typa or only asynonym. Pro- 
fessor E. L. Bouvier kindly lent me a specimen of ©. typa 
marked “Type, Ouoy and Gaimard, Nouv. Zélande” ; it agrees 
completely with my specimens of C. neo-zealanica, and 
the latter name must therefore be considered a synonym. It 
may be added that the mandibles are unusually short and 
peculiarly bent. Besides C. typa and C. neo-zealanica 
five other species have been referred to Cassidina. C. 
emarginata (Guér.) differs strongly from C. typa in epis- 
tome, antennule, mandibles, maxillipeds, and pleopods; it is 
established above as the type for Cassidinopsis (n. gen.) 
belonging to the eubranchiate Spheromine. C. latistylis 
(Dana) is with a little doubt considered a synonym to 
C.emarginata. C.maculata (Studer) cannot remain in 
Cassidina if Studer’s figure, showing the proximal joints of 
the antennulz as invisible from above, be tolerably correct, 
but as to the real relationship of this species I have no 
opinion. C.lunifrons (Richardson) must probably be re- 
ferred to Cassidinidea (n. gen.) (see below). C.laticauda 
(Whitelegge) differs, according to description and figures 
published by that author, in shape of epistome, palps of 
maxillipeds, and rami of plp.’ strongly from C. typa; it must 
therefore be removed from Cassidina and is very remote 
from Cassidinidea (n. gen.), but in spite of the lengthy 
description with five figures—occupying three pages—it is 
impossible for me to refer this species, not only to any genus, 
but to any section or group of the Spheromine. 
