358 31R. J. R. HENDERSON— A CONTRIBUTION 



Disti'ibntmi . From the Red Sea, Seychelles, and Mauritius, to China and the Pijis. 

 It has also heen lecorded from the Mediterranean, the Canaries, Madeira, and the 

 S. Atlantic. 



56. AcT^A RuppELLii (Krauss). 



A. Ruppelhi (Krauss), Miers, Ann. Mag. Nat. Hist. ser. 5, vol. v. jj. 232 (1880), uhi synon. 



Tuticorin, many specimens {Thurston). Common on the reef at Rameswaram {J. B. R.). 



The amount of pubescence varies greatly in different individuals. After examination 

 of the type of ^Egle rugata, Adams & White, I have come to the same conclusion as 

 Hilgendorf and Miers, viz. that it is merely a variety of the present species. A. hirsu- 

 tissima, Riipp., is also closely allied and perhaps not distinct. 



Blstrihutiou. Natal, Zanzibar, Mauritius, Malay Archipelago, N. and X.E. Australia. 



Genus Hypocceltjs, Heller. 



57. Htpoccelus rugostjs, n. sp. (PL XXXVI. figs. 9-11.) 

 Tuticorin, two females {Thurston). 



This species is closely allied to S. granulatus (De Haan), which has been well described 

 and figured by both De Haan and A. Milne-Edwards, so that only the characters wherein 

 it diflFers from the latter need be pointed out. The areolation of the carapace is very 

 like that of S. granulatus, but the granules are much smaller. The posterior half of the 

 lateral margin of the carapace is irregular and three-toothed, the most anterior tooth 

 being well-defined, and marking tlio hinder limit of the pterygostomial cavity ; whereas 

 in S. grannlatus this margin is slightly irregular, but not dentate. The pterygostomial 

 cavity has the upper and lower margins straight, and gradually converging to a rather 

 broad truncated hinder end, which is fully half the width of the anterior end ; whUe in 

 S. granulatvs the loAver margin of tlie cavity is strongly curved and the hinder end 

 narrow and pointed (see PI. XXXVI. fig. 12); in our new species the cavity also 

 approaches nearer to the orbit. 



In both species the chelipedes are somewhat similar in general appearance. In 

 S. rugosus the carpus is more strongly tuberculate, and the granules on the outer surface 

 of the hand are arranged in reticulating lines, while the upper surface is convex and 

 covered with prominent granular tubercles; whereas in the longer known form the 

 granules on the outer surface of the hand are arranged in moi-e or less parallel lines 

 along the joint, and the upper surface is flattened or almost concave, with a median and 

 two lateral granulated lines on this area. The ambulatory legs are also more strono-ly 

 tuberculated in the new species. 



The gastric and branchial regions of tlie carapace are reddish (in spirit specimens), 

 whUe the carpal joints of the chelipedes, and the legs, show traces of the same colour. 



All the comparisons have been made Avith a single dried specimen of //. granulatus 

 (locality unknown) in the collection of the British Museum. 



In the larger specimen the carapace is 12-3 mm. long and 17-5 mm. Ijroad ; the front 

 is 5'3 mm. broad. 



