290 MR. G. S. BRADY ON EUROPEAN CYPRIDINID.E. [Apr. 4, 



cornis is at some seasons abundant on certain parts of the British 

 coast, B. brenda has never been met with, except very sparingly, 

 and in only two localities. 



The following is a brief abstract of Sars's remarks on this subject : 

 — "I had long remarked that all the individuals of Philomedes 

 longicornis appeared to be males ; there were no egg-bearing females ; 

 but it did not occur to me to look for the female in so different a 

 form as C.globosa {brenda), especially as I had already found what 

 appeared to be the male of that species. But we find in other 

 Crustacea (Apseudes anomalvs and certain Cumacea) two forms of 

 males, — one and much the commoner form being very similar to the 

 female, the other and scarcer differing in many important details, 

 especially in the great development of the eyes and antennae. The 

 parts of the Cypridinidae which appear to be least liable to alteration 

 are the mandible-palp, the last pair of jaws, the ringed appendage 

 ("oviferous foot"), and the postabdominal lamina; and these parts 

 are all alike in Cypridina ylobosa and Philomedes longicornis. A 

 further confirmation of the truth of my view is, that I have found a 

 similarly formed male of a closely allied species, P. lilljeborgii. 

 This differs from P. longicornis in having the postero-inferior spine 

 of the shell more strongly developed, the ringed appendage showing 

 also the same distinctive marks as does that of the female, in having 

 only about nine spines instead of thirty as in C. glolosa." 



Among a number of Ostracoda dredged at various depths in the 

 Fosse de Cap Breton (Bay of Biscay) by M. le Marquis de Folin, 

 and sent to me for identification, were several specimens of a very 

 remarkable undescribed species, one of which was so far different in 

 size and form from the rest, though retaining the same characters as 

 to shell-sculpture, that I immediately took it to be the male of the 

 more abundant female form. And on further examination the 

 smaller example proved to have all the anatomical characters of Lill- 

 jeborg's genus Philomedes, while the larger ones belonged to Brady- 

 cinetus, Sars. The shell-structure is here of so novel a type (no 

 similar deep excavation and ribbing having heretofore been noticed 

 among the Cypridinidae) that I could no longer doubt as to the 

 sexual relations of Philomedes and Bradycinetus in this instance ; 

 and I was therefore disposed to regard Sars's case as proved with 

 respect also to P. longicornis and B. brenda. This conclusion, how- 

 ever, I had adopted too hastily, as will presently appear ; for in the 

 same gathering (Cap Breton) were found several examples of a Philo- 

 medes (PI. XXVI. fig. 1) agreeing in general aspect with "P. longi- 

 cornis," but rounder in lateral outline and more tumid, having also 

 a reticulated shell-structure exactly the same as that of the common 

 form, but differing constantly in the presence of two well-marked 

 sharp spines on the postero-superior and postero- inferior -angles of 

 the shell. Anatomical investigation showed that this was in fact the 

 true female of P. longicornis, the only appreciable differences con- 

 sisting in the shortened filaments of the upper antennae, and the 

 smaller development of the eyes, mandibular feet, and secondary 

 branch of lower antenna, the vermiform appendage and abdominal 



