27 



areas on the side of the carapace. The four spines on the antero-lateral regions 

 of the carapace are present but are very weak and flexible, and there is a fifth 

 spinule situated on the cervical groove about midway between the true bran- 

 chiostegal spine and the gastric carina. 



All the abdominal terga are carinated, though those of the first two are 

 incomplete and flaccid : the boundary between the terga and the shallow pleura 

 is, in all the somites defined by a well marked ridge. The 6th abdominal somite 

 is not longer than the 5th. The telson is a good deal shorter than the endopo- 

 dite of the caudal swimmeret. 



Eyes deficient in pigment, not very much wider than their stalk. The 

 antennular flagella are broken, but appear to have been very long. 



The external maxillipeds are a little shorter than the third pair of thoracic 

 legs. The 4th and 5th pairs of thoracic legs are by no means filamentous, the 

 5th pair, which are the longest, are as long as the rostrum and carapace together 

 with the first two abdominal terga. 



The tubercles on which the oviducts open are extremely prominent, nearly 

 meeting across the sternum : a pair of foliaceous lobules on the coxeb of the 

 4th pair of legs, in the female, also nearly meet across the sternum : these and 

 two rounded eminences situated, one behind the other, in the middle line of the 

 sternum form the " thelycum." 



In the largest specimen the carapace and rostrum measure 80 millim., the 

 extended abdomen 110 millim. in the mid-dorsal line. 



Arabian Sea, in the neighbourhood of the Laccadives, 1140 and 1200 

 fathoms. 



In the originally-printed diagnosis the epipodites have, by mistake, got 

 shifted down a line, so that the appendages of somite VIII are shown without 

 an epipodite and those of somite XIV with one. 



Regcl. Nos. -j- (Type of the species) : — . 



Everyone agrees that Hymenopeneus S. I. Smith, identical with Haliporus, Spenee Bate ; and 

 the name Haliporus has the priority. 



I propose to retain the name Hymenopeneus in a subgeneric sense, for the species in whicb, as 

 in H. taprobanensis and villosus, the last two pairs of thoracic legs are not flagelliform. 



Subfamily AristWlllW. 



Aristjeus, Duvernoy. 



Aristeus, Duvernoy, Ann. Sci. Nat. Zool. (2) XV. 1841, p. 101 : Wood-Mason, Ann. Mag. Nat. Hist., Oct. 1891 

 p. 278. 



Carapace with a well developed rostrum, which is toothed dorsally only : 

 abdomen long, with some of the somites compressed and their terga carinated. 



