38 



dite, as it is in A. edirardsianm. The third pair of the legs reach beyond the 

 tip of the external maxillipeds. 



The third pair of legs are not abnormally longer than the first and second, 

 the carpus in all being an elongate joint. The fourth and fifth pair of legs have 

 setiforra dactyli, and the fifth pair reach beyond the tip of the antennal scale. 



The exopodites of the 1st pair of abdominal appendages are about as long 

 as the first 5| abdominal somites. 



The " thelycum " is a long, moderately acute, subpentagonal plate placed 

 between the 4th pair of legs and followed by a transverse ridge between the 

 fifth pair. In the male an elliptical tubercle followed by a small tooth corres- 

 ponds with the " thelycum." 



The andricum consists of a pair of loosely-interlocking subtriangular plates, 

 the outer edge of which forms a free and independent process distally. 



Though the first 3 abdominal sterna are, as usual, prominent and subacute 

 in the middle line, they do not form pronounced uncate processes. 



Colour in life, bright orange. 



In the unique female the carapace and rostrum are 75 millim. long and the 

 abdomen is 74 millim., measured in the mid-dorsal line. The unique male is 

 larger, but has the rostrum broken. 



Bay of Bengal, near the Andamans, 561, fathoms : Arabian Sea, between 

 the Laccadives and the Malabar coast, 824 fathoms. 



This species, as the name implies, was luminous in life, the luminous secre- 

 tion coming from, or from somewhere near, the openings of the green glands. 



At first sight A. coruscans may be confused with A. crassipes, but the 

 different branchial formula, the slender meri of the first 3 pairs of legs, and, in 

 the male, the different form of the external maxillipeds at once distinguish it. 



Regd. Nos. (Type of the species) : . 



Subgenus ABIST^OMOEPHA. 



Aristseomorpha, Wood-Mason, Ann. Mag. Nat. Hist., Oct. 1891, p. 286. 



Ariiteus (part) Spence Bate, Challenger Crustacea Blacrura, p. 317 (Aristeus rostridentatus). 



Rostrum many-toothed. A hepatic spine, as well as an orbital (post-anten- 

 nular) and branchiostegal (post-antennal). 



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



Terminal joint of mandibular palp triangular. Exopodite of the 2nd 

 maxillipeds stiff, compressed, very much longer than the endopodite. Dactyli 

 of the last two pair of legs setiform. 



