Report on the zoological collections made in the Indo-Pacific Ocean ...

1CRUSTACEA. 24ambulatory legs. The ej-e-peduncles are very short and thick, withvery large corneas ; the antennules are transverse ; the basal jointof the antennae is slender, and although longer than the two followingjoints, does,not reach to the subfrontal process ; the ischiumjointof the outer maxillipedes is rather short and broad, but longerthan the next joint and longitudinally sulcated ; the merus isquadrate, the slender exognath reaches to the distal end of themerus. The chelipedes are subequal and of moderate size, and, asalready stated, pubescent ; the merus or arm is trigonous and has atooth near the distal end of its upper margin ; the carpus is armedwith a strong spine on its inner surface ;palm somewhat shorterthan the fingers, the margins not cristated, the fingers regularlydenticulated and meeting along their inner margins and acute attheir apices, but without a tuft of hair at base. The ambulatorylegs are slender, with the joints somewhat compressed and scantilypubescent ; the margins of the penultimate and terminal joints of thelast pair of legs are fringed with long hairs, but the terminal jointof the last pair of legs is styliform and not dilated. The bases ofthe male verges lie in wide open canalicuU of the sternum, and theseorgans (in the single specimen examined, which is probably notadult) are nearly straight. Colour (in spirit) whitish. Length ofthe carajiace of the male 3| lines (nearly 8 millim.), breadth 4| lines(nearly lU millim.); length of chelipede when fully extended nearlyI inch (12 millim.), of second ambulatory leg about 7g lines(16 millim.).Two specimens, one a male and the other sterile, were collectedin the Arafura Sea, 32-36 fms. (No. 160).Haswell's types were from Holborn Island, Port Denison (20 fms.).As, in his brief description, he does not mention the pubescence ofthe carapace, and as his specimens differ in coloration, it is possiblethat ours are distinct ; and if so, I would propose to designatethem P. hasivelli.Garcinoplax vestitus*, as figured by De Haan, differs in its somewhatnarrower front, in the shorter, less prominent third antero-lateralspine, more quadrate carapace, less compressed chelipedes, and in theabsence of long cilia from the terminal joint of the dactyli of thefifth ambulatory legs.The distinctions between the genera Carcmoplax, Eucrate, andPilumnoplax of Stimpsonf are very slight, and a revision of thegroup is urgently needed. If, as is probable, all three genera shouldhave to be united, the designation Pseudorlwmhila will, I think, takeprecedence, since De Haan's name Eucrate differs by a letter onlyfrom the earlier name Eucratea, and Curtonotus had previously beenused in the Coleoptera.* Cancer {Curtonotus) vestitus, DeHaan, in Siebold, Fauna Japonica, Crust,p. 51, pi. V. fig. 3(1835).t Proc. Acad. Nat. Sci. Philad. p. 93 (1858).