40 



2nd and 3rd, having, as in Arist&us edwardsiamis, a short and broad carpus. 

 The slender 5th pair of legs almost reach to the tip of the antennal scale. 



The exopodites of the 1st pair of abdominal appendages are a little more 

 than half the length of the abdomen (without the telson). 



The " thelycum " is a pointed plate, lying between the 4th pair of legs, and 

 followed by a denticle, lying between the 5th pair. There is a sharp tooth in 

 the middle line of the first 3 abdominal sterna. 



In the unique female the carapace and rostrum are 73 millim. long, and the 

 abdomen is 80 millim. long, measured in the mid-dorsal line. 



Andaman Sea, 271 fathoms. 



-r- -i -vr 8559 



Regd.ISo.-g-. 



Subgenus AEIST^EOPSIS. 



Aristxus (part) Spence Bate, Challenger Crustacea Macrura, p. 312 (A. armatus). 

 Aristxopsis (part) Wood-Mason, Ann. Mag. Nat. Hist., Oct. 1891, p. 284 (A. armata). 



Rostrum 3-toothed, long in both sexes. Cervical groove indistinct. An 

 orbital (post-antennular) and a branchiostegal (post-antennal) spine. No hepatic 

 spine. 



The last 4 abdominal terga are carinated, each carina ending in a spine. 



Th6 terminal joint of the mandibular palp is triangular. The exopodite of 

 the 2nd maxillipeds is much shorter than the endopodite, and is slender and lax. 

 The dactyli of the last pair of legs are lanceolate. 



The third pair of legs has a podobranch and the 4th pair an epipodite. The 

 pleurobranchix are similar in structure to the other branchiae and are of nearly 

 normal size. 



The branchial formula is as follows : 



Total 



5 + 7 ep. 



= 24+7ep. 



