257 



The abdomen is long and narrow ; the first segment is concealed under the carapace, 

 the third and the fifth segment are the longest. 

 Dimensions in mm. : 



Fronto-orbital distance . . 3.3 

 Length of carapace . . . 6.4 

 Breadth of carapace . . . 6.4 



3. Pinnotheres obesns ■Xy-&.W3i. PI. 17, Fig. 3. 



Stat. 174. Warn Bay, north coast of Ceram. Depth 18 m. i cf- I" Area. 



Of such small individuals as are generally met with among Pinnotheres, lacking any 

 dentation or special markings on the carapace and subject to variations in the outline of the 

 latter, the identification is often troublesome. Yet the present example so much resembles 

 Dana's figure of P. odestis as to render its identification with this species very likely. The 

 carapace is s-ubcircular, narrowed anteriorly, the iront advanced, bilobed, the antennae rather 

 long, (but this is for the most part due to the fact that the last joint of the flagellum, which 

 consists, as usual, of only two segments, is provided with some long hairs at the tip, among 

 which hairs some mud or detritus is retained). The external maxillipeds, too, agree with those 

 of Dana's species in the pronounced antero-internal angle of the merus, in the elongate and 

 slender propodus, and in the dactylus, but whereas in Dana's figure this dactylus 

 does not quite reach the end of the propodus, it does so exactly in m )• 

 specimen (fig. 3(7); in its description Dana does not state anything about this dactylus^), 

 but MiERs' specimen agrees in this respect with mine. 



The chelae are greatly swollen, palm longer than fingers, movable finger with an 

 obliquely-directed tooth near base of cutting margin, fitting into a notch at the opposite margin; 

 Dana depicts two very minute teeth on the movable finger. 



Walking legs rather robust, much more so than in Dana's figure, the last pair by far 

 the shortest and weakest, all dactyli subequal in length, falciform, but those of the last pair 

 are somewhat more slender, less curved, and with some few hairs along inner margin ; there 

 are also some hairs along the posterior margin of these legs. 



The abdomen is rather narrow, bottle-shaped, regularly tapering; first segment shortest, 

 second segment twice as long, all following segments longer and of subequal length. 



If my specimen is really identical with P. obcstts, there is no serious objection to unite 

 P. siamensis Rathbun with it. In some respects (external maxillipeds, shape of walking legs) 

 the present specimen even agrees better with the latter species, though the antennae are very 

 much longer and the flagellum is represented as consisting of 3 — 4 long joints. The shape of 



I) Dana's original description not being accessible to me, Dr. de Man has had the kindness to transcribe it for me. 



It must be stated here that A. Milne-Edwards (Nouv. Arch. Mus. Paris, t. 9, 1873, p. 318; declared Pimwihercs globosus 

 Jacquinot et Lucas to be identical with Dana's species, after comparing original specimens of both these species with individuals from 

 New Caledonia. With all respect due to the memory of the able French carcinologist I cannot decide to follow him, though the dactylus 

 of the external maxillipeds in P. globosus (see H. Milne-Edvvards, Ann. Sc. Nat. (3), t. 20, 1853, p. n, f. 6) does not quite reach the 

 and of the propodus, just like in my specimen. 



109 



