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Show 1900.] FROM THE FALKLAND ISLANDS. 561 and value as the ' Histoire Naturelle des Crustace's,' 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 C. 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 Sphaeromidae. 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. maculata Studer, 11 m m . 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 C. emarginata. 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 antennae. 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. emarginata, 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 C. 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 peraeon 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 tbe 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 |
