25 



This species is represented in the South Atlantic, East of Buenos Ayres, by Hoiiip. speciosus 

 Sp. Bate, which differs by the posterior half of the 3"' abdominal somite being elevated to a 

 small carina and by a few other differences. 



General di st ri b u t i o n : Arabian Sea, in the neighbourhood of the Laccadives and 

 Malabar coast, Gulf of Manar, Bay of Bengal, Andaman Sea (Wood-Mason and Alcock). 



75. Hemipejtaeus Sibogae n. sp. 



Stat. 52. April 20. 9'3'.4S., 119° 56'./ E. Savu Sea. looo m. Globigerina ooze. i adult female. 



Closely related to Hcuiip. crassipes (W.-Mas.). 



Carapace, abdomen and appendages covered with a dense, though fine tomentum. 

 Rostrum hardly reaching to the tip of the antennal scales, distinctly shorter than the carapace, 

 the length of the rostrum (28 mm.) being about '/c that of the carapace (34 mm.). The three 

 teeth of the rostrum are less prominent than in the female from Stat. 85, which was referred 

 to Hciiiip. crassipes, and the distance between the i^' and the 2"<i tooth, when compared with 

 that between the 2"'^ and the 3''^, is a little shorter than in that female ; the three teeth are 

 situated in the same horizontal line, while in the female of crassipes a line uniting the tips 

 of the teeth appears distinctly arcuate. The free part of the rostrum is slightly recurved and 

 is much shorter and much less slender than in the female of Hemip. crassipes. 

 The post-rostral crest is traceable as a blunt and low ridge, though rather inconspicuously, to 

 midway between the cervical i. e. gastro-hepatic groove and the hinder margin of the carapace. 

 The two spines and crests on the latter are as in Hemip. crassipes, but the still more strongly 

 marked, cervical groove distinctly indents the dorsal ridge, while, as in Hemip. crassipes., 

 the post-cervical groove does not indent it ; the post-cervical groove is less strongly marked 

 than the cervical, nearly as in the other species of the genus. 



Fourth to 6* abdominal terga carinated, each carina ending in a spine. Measured 

 along their upper margin the proportion between the length (9 mm.) of the 5* abdominal 

 somite and that of the 6''^ (16,5 mm.), appears nearly the same as in Hemip. crassipes and the 

 proportion between the length (16,5 mm.) and the width (10,5 mm.) of the 6* somite is also 

 about the same, though in the female of Hemip. crassipes the somite appears a trifle less 

 wide (viz. 10 mm.) in regard to the length (17,5 mm.). Telson armed at either side with 4 

 spinules, caudal fan as in Hemip. crassipes. 



Eyes black,^ wider than their stalk and a little smaller in proportion to the length of 

 the stalk than in Hemip. crassipes, the tubercle a little less prominent. Antennules as in this 

 species, the antennal scales a little wider. E.xternal maxillipeds extending to the extremity of 

 the penultimate article of the antennular peduncle. 



Legs of i^' pair a little longer than the external maxillipeds, as long as the antennular 

 peduncle, 3''^ legs just reaching beyond the rostrum and the antennal scales. As in Hemip. 

 crassipes, the meri are broad and compressed, the chelae and the fingers very long, but the 

 carpi and the chelae are co m pa r a tively shorter and less slender. So e. g. are the 

 meri of 3''' legs 17 mm. long and 3 mm. broad; the carpi are 17,5 mm. long and 2 mm. thick 



SIliOG.\-EXPEDITlE XXXIX I7. 



