169 



143 The mouth cone projects markedly. The outer lobes of the maxil- 

 lipeds are longer, abruptly tapering distally; the inner lobes are not armed 

 and roughly 1/8-1/6 of the outer. 



Pereopods I are roughly equal in length to pereopods II but stronger; 

 the anterior part of the broadened, oblong-oval 6th segment is com- 

 pressed in the form of a plate, its anterior distal angle produced into a 

 small acute denticle projecting above the claw, which makes it possible 

 to readily differentiate this species from the other larger species of the 

 genus Scina. Pereopods III and IV are similar in structure, their 4th seg- 

 ment broadened distally and considerably shorter than the mutually equal 

 6th and 5th segments; the claw is long, thin, and slightly curved. Pere- 

 opods V are longer than the rest, their 2nd segment considerably shorter 

 than the 4th, 5th, and 6th segments together; the anterior and posterior 

 margins of the 2nd segment are finely denticulate, the distal process is 

 slighdy longer than the 3rd segment and bears two very distinct den- 

 ticles on the anterior margin; the 6th segment is insignificantly shorter 

 than the 5th. Pereopods VI are only slightly shorter than pereopods V; 

 their 6th segment is longer than the 5th, which in turn is longer than 

 the 4th segment. Pereopods VII are small, their 6th segment longer than 

 the 5th while the latter is shorter than the 4th. The claws of pereopods 

 V-VII are short and slightly curved. 



Uropods I are finely denticulate on the posterior margin. The 

 basipodite of uropods* III is smooth while the endopodite is finely 

 denticulate on the anterior and posterior margins. 



Distribution: This is a panoceanic species and does not enter the 

 Arctic Basin nor the Antarctic region. It is known from the Atlantic 

 (from 46° 15' N, 50°09' W to 35° 18' S, 19°00'W), Pacific (from the 

 Bering Sea up to 41° 19' S, 177°44' E) and tropical regions of the Indian 



144 Ocean, including the Arabian Sea. It is common in the 200-1,000 m 

 layer but more often found at depth of 5(X)-750 m. It is one of the most 

 common species of the genus Scina. 



5. Scina langhansi Wagler, 1926 (Fig. 63) 



Wagler, 1926: 335; Vinogradov, 1964: 131. 



Length of sexually mature specimens 8-10 mm. 



The pereon is broadly oval and smooth. The pleon has a weakly 

 developed keel. 



Antennae I are roughly equal in length to the pereon. The mouth 

 cone is relatively small and barely projects. The outer lobes of the max- 

 illipeds are small and markedly tapering distally; the inner lobes are 

 weakly developed and distally only 1/5 the length of the outer. 



Changed from Russian original by author — ^Eds. 



