108 



The abdominal terga — even the 3rd — are quite smooth and non-carinate. 



The antennules and antenna? are as in H. gibbosus, except that the antennu- 

 lar flagella are as long as the body minus only the telson. 



Except that the 1st pair of legs are longer and reach further beyond the 

 antennal scale, the legs and external maxillipeds have the same structure and 

 proportions — both inter se and with regard to the rest of the body — as those of 

 H. gibbosus : moreover the spines on the posterior border of the carpus of the 

 last three pairs of legs are as large as those on the posterior border of the 

 merus. 



In an egg-laden female the length of the rostrum is 21 millim., of the cara- 

 pace 24 millim., of the abdomen 49 millim. 



Found only in the Arabian Sea, in the neighbourhood of the Laccadives 

 and northwards, in 865-880 and 890 fathoms. 



Colour in life, pink. 



Kegd. Nos. 9 -^^- 6 (Types of the species) : 3 ^ 3 . 



63. Heterocarpus Wood-masoni, n. sp. 



Illustrations of the Zoology of the Investigator, Crustacea, Pl. LI. Fig. 2. 



The following are the diagnostic points : — 



Rostrum long, serrated dorsally and ventrally, and continued nearly to the 

 posterior border of the carapace as a carina which is very indistinct behind the 

 gastric region where it carries its only two teeth. 



The true 1st or "postocular" carina, that in other species runs from the 

 middle of the orbital notch, is here entirely wanting. The true 2nd or " post- 

 antennular " carina, that in the other species is merely a buttress to the orbital 

 spine, is here a long carina running uninterruptedly from the posterior border 

 of the carapace into the orbital spine. The 8rd or " post-antennal " carina, 

 running from the posterior border of the carapace into the branchiostegal spine, 

 is very distinct, and lastly the marginal carina is unusually well defined. 



The abdominal terga are smooth, except for a compressed hump-like eleva- 

 tion in the middle of the 3rd. 



The 6th abdominal somite is as long as the telson and twice as long as 

 the 5th. 



Inter se the legs and external maxillipeds have much the same proportions 

 as in H. gibbosus, but they are slenderer and much shorter, none of them reach- 

 ing beyond the antennal scale. 



Two young specimens from the Andaman Sea : 265 fathoms. 



Regd. No. ^ (Types of the species). 



