1900.] FROM THE FALKLAND ISLANDS. 561 



and value as the ' Histoire Naturelle des Crustaces,' will be an 

 obvious reflection. But there is no reason to suppose that the 

 figures are by the distinguished author of that work, and it can 

 easily be proved that their accuracy is not beyond impeachment. 

 For example, in the figure of the maxillipeds of G. typa there is a 

 joint missing ; and if this corresponds with the reality, it would 

 falsify the author's own statement that in this genus the mouth- 

 organs correspond with those of the Sphseromidse. It is most 

 likely that Milne-Edwards had but one specimen, and that this one 

 was dissected, and that the fragments, after they had been figured, 

 were not thought worth preserving. In that case, the question 

 here raised will perhaps never be answered with certainty. 



C. metadata Studer, 11 mm. long, presents a different set of 

 difficulties. Its colour has been already mentioned, together with 

 the fact that it comes from Kerguelen, whence Miers records also 

 0. emargmata. From this species, which was well known to 

 Studer from South America, he distinguishes his Kerguelen species 

 by the form of the pleo-telson, the narrowness of the inner branch 

 of the uropods, and the length of the antennse. Of these 

 distinctions the last seems non-existent, but the other two make 

 a rather close approach to what is shown in the ventral view of 

 C. typa, the caudal shield being triangular, produced to a narrowly 

 rounded point a little beyond the inner lobe of the uropods, this 

 lobe being lanceolate with convex outer and concave inner margin, 

 and prolonged much beyond the small outer ramus. A frontal 

 view of the head shows a shape corresponding with that of C. emar- 

 ginaia, except that the rostrum (described in the text) is omitted 

 in the drawing. But to this species Studer attributes " three free 

 short pleon-segments " in front of the caudal shield, and figures 

 them quite distinctly with unbroken lines running across the back, 

 which cannot be reconciled with the statement of Milne-Edwards 

 in his generic account, borne out by his dorsal view of 0. typa, 

 that " the pleon, as usual in this tribe, is composed of two portions, 

 the anterior formed of several segments soldered together towards 

 the middle of the body, but distant [? distinct] laterally, the other 

 posterior portion being shield-shaped." The front part of the 

 pleon in C. emarginata is accurately described by Pfeffer. It 

 clearly consists of four segments ; the first much narrower than 

 the rest, so short that it is apt to be concealed, but having its distal 

 margin dorsally uninterrupted ; the second rather remarkable, not 

 only for its width, but for the fact that its sides are longer than 

 any side-plates of the perseon and enclose the two following- 

 segments, with both of which it is in coalescence at the middle of 

 the back ; the third segment having its acute lateral apices bent 

 round so as to rest on the front margin of the caudal shield ; the 

 fourth ending similarly within the third, but projecting a point 

 on to the front margin of the caudal shield on each side at a short 

 distance within its own lateral apex. Of such details the figure of 

 C. typa is to a large extent innocent, showing, however, the last- 

 mentioned projecting points, and three segments coalesced in the 



