148 
“ TERRA NOVA ” EXPEDITION. 
/irjJ.l.y-M 
basis itself, although its relation to the longer distal segments is much the same as in 
C. elegant. In the first legs the distal segments are together distinctly longer than 
the basis. 
A male specimen has a total length of 5' 6 mm. The general form agrees closely 
with that of the male C. elegant, but the disposition of the ridges of the carapace 
resembles that of the female described above. The lateral enclosed area is relatively 
smaller than in the female. The carapace differs from that of the male C. elegant in 
having no tubercle at the posterior lower corner of the enclosed area (although this 
tubercle may be inconspicuous in C. elegant, as in the specimen described above) and no 
ridge running thence to the hind margin, while the posterior vertical ridge forks at its 
upper end, the anterior limb of the fork forming part of the upper enclosing ridge. 
The surface between the ridges is somewhat coarsely but sparsely granulated. 
15. ('ydatpis negus, Zimmer. 
C. ar<jus, Zimmer, 1902, p. 444, tigs. A-C; id. 1913, p. 470, pi. xlvi, tig. 70. 
C. hi striata, Zimmer, 1902, p. 447, tigs. D-F; id. 1913, p. 470 ; Stebbing, 1913, p. 39. 
C. biplicata, Caiman, 1907b, p. 17, pi. iii, figs. 4—15; Zimmer, 1913, p. 470. 
Occurrence .—Stations 133, 135, and 136. Spirits Bay, near North Cape, New 
Zealand. Plankton, at HO metres, 3 metres, and surface. Many specimens. 
Remarks. - The majority of the adult females in this collection differ from the 
syntypes of C. biplicata in their greater size (total length 5*1 mm., as against from 
3 ‘ 6 to 4’2 mm.) and less strongly calcified integument; in having the dorsal edge 
of the carapace more strongly arched, the lateral ridges much less marked, not con¬ 
verging above, and situated a little further forward on the carapace; and in having 
the abdominal somites relatively more robust. In all these characters they resemble 
the immature female described by Zimmer as C. bistriata. They further differ from 
the syntypes of C. biplicata in having the posterior tooth of the crest of the caparace 
less abruptly defined, and all the abdominal somites with a strong dorsal keel; this 
keel is elevated towards the hinder end of each somite, forming a blunt tooth, so that 
the dorsal outline of the abdomen appears serrated. The fifth abdominal somite is 
hardly more than twice as long as deep, while in < biplicata the proportion is about 
two and a half to one. 
These characters leave little doubt that the specimens belong to the same species 
as the holotype of Zimmer’s C. bistriata, and they might have been urged as evidence 
for the distinctness of that species if it had not been for the presence of some distinctly 
smaller females from Station 136. One of these, an ovigerous female, measures only 
4 • 6 mm. in total length, and while it agrees with the others in the outline of the 
carapace and in the character and approximate position of the lateral ridges, it has 
the dorsal keel of the abdomen much less conspicuous and the somites much more 
slender, the fifth, for instance, being 2 * 3 times as long as deep. In general appear¬ 
ance, as in size, this specimen is, to a great extent, intermediate between the syntypes 
