336 



36 



folded against Ihe merus, reaches a little beyond the inner angle of the latter; the 

 propodus is short and broad; the dactyhis articulates near the middle of the pro- 

 podus, which it overreaches a liltle, and the terminal half of which it resembles. 



Hands inflated, fingers slender, gaping. Length of legs, 2 (longest) -Sl-i; 

 dactyli similar, strongly curved, terminal half very slender, fourth a little shorter 

 than the others, which are subequal ; fourth merus much shorter than the others. 



Length of type male 11 mm., width 102 mm. 



Type locality. — South of Koh Kut, 17 — 20 fath., mud; I. 28; 1 J*. 



Pinnotheres siamensis Ralhbun. 



Pinnotheres siamensis Rathbun, Proc. Biol. Soc. Washington, XXII, 111. 1909. 



Male. — Similar to P.kiitensis; dif- 

 fers as follows: The carapace is more 

 strongly angled behind the orbit; its sur- 

 face is deeply punctate. The front is plainly 

 bilobed. The antennse are as long as the 

 width of the front; in P. kutensis, they are 

 not discernible, perhaps broken off. The 

 palpus of the maxilliped is considerably 

 longer than in the related species, the pro- 

 podus especially elongate, the dactylus 

 attached on the distal half of the propo- 

 dus, not far from the middle, very narrow 

 and reaching just as far as does the pro- 

 podus. The palms of the chelipeds are 

 much swollen, their upper and lower mar- 

 gins very convex. The carpal and propo- 

 dal segments of the legs are wider in the 

 distal half than in the preceding species; dactyli of all the legs subequal. The ster- 

 num is hollowed out in a circular depression which receives the extremity of the 

 abdomen. 



Length of type male 11 mm., width 1 05 mm. 



Localities. - South of Koh Kut, 17—20 fath., mud; L 28; IJ" (type). North 

 of Koh Chuen, 15 fath., mud, shells; II. 5; 1 <?. 



In the specimen from Koh Chuen, the abdomen projects behind the carapace 

 and sternum in a hemispherical protuberance visible in a dorsal view; in the type 

 specimen the abdomen is a good deal rumpled, so that one cannot be sure that 

 its normal arrangement was as in the cotype. 



Subfamily Pinnotherelinæ. 

 Mortensenella Rathbun. 



Mortensenella Rathbun, Proc. Biol. Soc. Washington, XXII, 111, 1909. 



Dorsal aspect of Pinnixa, the carapace being very broad, subpenlagonal, and 

 the last leg reduced in size. Maxillipeds not gaping, filling the buccal cavity, with 



Fig. 20. Pinnotheres siamensis, t.ypc c?, 1-05 mm. 

 wide: a, dor.sal view; 6, abdomen; c, maxilliped. 



