18G 
14. C'furca , Elir. ; Kent, 1. c. p. 455, pi. 25, f. 31-32. Bergh. 
1. c. p. 195, pi. 12, f. 1-3 ; pi. 13, f. 13-20. Gourret. Ann. 
d. Mus. d’llist. Nat. Marseille Mem. No. 8, 1883, p. 45-47, 
pi. iv., f. 58-59, 67-68. 
There seem to be two well marked forms, which may be regarded 
as varieties of this species. Besides the typical form (Bergh. 
figs. 13-20) there is the C. pentagonum , Gourret, and its variety 
rectum (pi. 4, f. 58-59), which are fairly constant in size, shape, 
length of horns, and the strongly areolate cuirass. One of the 
specimens which came under my observation had nearly the whole 
of the areolate plates broken away, and there remained a rigid 
homogeneous shell, having the same shape as those in which the 
plates were intact. This fact suggested to my mind two questions, 
to which as yet I am unable to find answers : Is the cuirass 
double ? or does the individual cast it off naturally when it is too 
small, and secrete a larger one ? 
The forms described by Gourrett, under the following names, 
C. dilatatum and its variety parvum , and G. globatum were well 
represented in my gatherings, and seemed to be constant as to 
length of horns, sculpture, &c. ; the only noticeable variations 
appeared to be in the form of the body and the distance between 
the posterior horns. In some specimens the body was well 
rounded and the horns but a little distance apart ; others had 
the body compressed and the horns widely separated, whilst many 
examples had a deeply concave ventral surface, and the aspect of 
the body when viewed from behind exhibited a cresentic outline, 
with the horns closely approximate, and the dorsal surface 
strongly convex. 
Obtained in tow-net off Green Point (very common). 
15. C. gravidum , Gourret, 1. c. p. 58, pi. 1, f. 15. 
In the description of this species the (inferieure) anterior 
portion of the body is described as globose. The specimen met 
with by me had the body strongly compressed, otherwise it agrees 
with the description and figure. 
Surface, off Green Point, P. J. 
16. C . tripos , Mull. ; Kent, 1. c. p. 454, pi. 25, f. 24-33. Bergh. 
1. c. p. 204, pi. 12, f. 4-6, pi. 13, fig. 21-27. Gourret, 1. c. 
pi. 1, f. 1,2, 3-7, pi. 2, f. 33-35. 
This is a very variable species, scarcely any two individuals 
being found alike. The references given above indicate the 
varieties observed. 
Very common in surface gatherings off Green Point, P.J. 
17. C. liirundinelldy Mull. ; Kent, 1. c. p. 457 ( C . longicorne ), and 
p. 859, pi. 25, f. 26. Bergh. 1. c. p. 215, pi. 13, f. 12. 
Biitschli, 1. c. pi. 53, f. 9, a-b. 
As far as I have been able to ascertain, this species has not 
hitherto been found in salt water. After a very careful examina- 
