OCR Text |
Show 522 REV. T. R. R. STEBBING ON CRUSTACEANS [May 22, curved and compressed. The tail of the male is 6-jointed and deeply notched on each side about the middle. The outer pedi-palps, as in Hymenosoma, are covered on the outside with short hairs." It seems a fairly clear and innocent account, till you begin to work with it. White assigns to his subgenus two species, the second being Hymenosoma depressum Jacquinot, which in 1852 was referred to Hymenicus by Dana. Miers, however, in 1876 informs us that the specimens referred by White to Jacquinot's species are distinct from it, and he names them Elamena whitei. White's first species is Halicarcinus planatus, with the synonymy Leucosia planata Fabricius, Hymenosoma leachii Guerin, and Hymenosoma tridentatum Jacquinot. This last synonym is accepted without reserve by Milne-Edwards in 1853, by Heller in 1868, and Tozzetti in 1877, all of whom quote it accurately from Jacquinot's plate as Hymenosoma tridentata. It is accepted with doubt by Dana in 1852, by Miers in 1876, and by Haswell in 1882. Miers drops the query in 1879, and inferentially in 1886. Lucas in 1853 describes under the name " Hymenosoma ? tridentatum," not Jacquinot's specimen, but Jacquinot's figures of it, adding the information that it was taken under stones at low-tide on the coasts of the Auckland Islands, and proposing to make it the type of a new genus Hombronia, most likely in total ignorance of White's Halicarcinus. In 1885 Filhol states that Halicarcinus pilanatus has been recorded from the Auckland Isles by Hombron and Jacquinot, and then proceeds to establish as a separate species Halicarcinus tridentatus (Jacquinot & Lucas), of which he gives a figure (pi. 50. fig. 3), having found the species, he says, in Cook's Straits. To the work in which Hombron and Jacquinot record H. planatus lie gives no clue. He does not refer in his text to his figure of H. tridentatus, which has a much less comparative width of carapace and much more slender chelipeds than the figure on Jacquinot's plate. He speaks of the description of this species given by Jacquinot and Lucas as being incomplete, which it might well be, since Jacquinot did not describe it at all, and Lucas only described what Jacquinot figured. It is difficult to tell whether Lucas is quite serious about some of the details, but he had no specimen by which to control the drawings. M. Filhol tells us that the maxillipeds present very slight differences from those of //. planatus, but what those differences are he neither says nor shows, though Jacquinot's figure, with the last joint attached in the middle of the penultimate, absolutely excludes Halicarcinus. That the carapace is without lateral teeth M . Filhol does mention, and this may well be in agreement with Jacquinot's species, but it is contrary to the character of Halicarcinus given by White. White's other synonym, Hymenosoma leachii Guerin, is not wholly free from difficulty, for though Dana, Miers, and Haswell accept it as identical with A. planatus, Milne-Edwards (1853) upholds it as an independent species, and Miers in 1886 regards Halicarcinus ovatus Stimpson as the representative on the Australian coast of |