234 



The outer lobe of maxillae I is armed on the distal margin with only a 

 single spine while the distal end of the inner lobe is almost straightly 

 truncated. The outer lobes of the maxillipeds are amygdaloid and in the 

 distal part of the inner margin bear only two short setae; the unarmed 

 inner lobes fall far short of 1/2 the length of the outer lobes, and their 

 distal margin is rounded. 



The claws of pereopods I and II are longer and broader than in 

 S. spinosa; the lobe on the 5th segment of pereopods I is strongly devel- 

 oped and, moreover, the 6th segment also has a weakly developed lobe. 

 In pereopods III-V the 6th segment is longer than the 5th, which in turn 

 is shorter than the 4th segment. The basipodites of the uropods bear 

 curved spines only on the anterior margin; on the posterior margin there 

 is a solitary spine opposite the place of attachment of the exopodite. 



Distribution: Found in the Indian Ocean in the cental region 

 (16°03' S, 90°06' E) and in the Arabian Sea in catches from depths 

 of 2,020-2,990 and 0-2,010 m. 



195 4. Genus Acanthoscina Vosseler, 1900 



Vosseler, 1900: 675; Wagler, 1926: 424. 



Differs markedly from the original form of the specialized genus. 

 Pereon somites I and II are fused. Pereon somites II-VII and pleon 

 somites I-III have dorsal denticles. The head has two lateral spines. The 

 eyes are small, well noticeable. Antennae I are longer than the pereon. 

 Antennae II are absent in both males and females. The mouthparts are 

 very small and reduced to a greater extent than in other scinids. Maxillae I 

 have a palp which is reduced to a small tubercle. Maxillae II have reduced, 

 small, apically tapering lobes. The outer lobes of the maxillipeds are 

 reduced to two small narrow plates; the inner lobes are absent. Coxal 

 plates II-V have prolonged and acute spines on the anterior and posterior 

 margins. Pereopods I and II are simple. The distal segments (4th, 5th, 

 and 6th) of the pereopods are fused. Pereopods VII are equal to or longer 

 than pereopods VI. The telson is free. The gills are located on pereon 

 somites II-VI. 



Type species: Scina acanthodes Stebbing, 1895. 



The genus includes two close species. 



KEY TO SPECIES OF GENUS ACANTHOSCINA 



1. Claws of pereopods I and II, 1/5-1/4 length of 6th segment; 2nd 

 segment of pereopods V, 1.5 times longer than 2nd segment of pere- 

 opods IV; 6th segment of pereopods VI roughly equal to 5th seg- 

 ment I. A. acanthodes (Stebb.) 



— Claws of pereopods I and II, 1/3-1/2 length of 6th segment; 2nd 

 segment of pereopods V almost twice longer than 2nd segment of 



