237 



Fig. 100. Acanthoscina birsteini Vinogradov, female (after Vinogradov, 1976). 



The lobes of maxillae II are separated, with prolonged tips, bearing 

 a single strong apical spine on each. The maxillipeds are very small; the 

 outer lobes are reduced to narrow, slightly proximally broadened plates, 

 armed with two strong apical setae on each; their outer margin bends 

 sharply near the base. 



Pereopods I and II are stronger than in A. acanthodes; the 2nd seg- 

 ment of pereopods I is roughly equal to the length of the 5th and 6th 

 segments together; the short 4th segment is almost equal to the 3rd; the 

 5th segment is somewhat shorter than the 6th which tapers distally; the 

 claw is slightly curved and strong. Pereopods II are weak. Pereopods III 

 and IV are long and thin; the 2nd segment is equal to the 4th and 5th 

 together; the 4th segment is shorter than the 5th, which in turn is shorter 

 than or equal to the 6th segment. The claws are very small and curved, the 

 2nd segment of pereopods V is relatively longer than in A. acanthodes; it 

 is triangular in cross section and armed on all three edges with numerous 

 thin spines. Pereopods VI are shorter but weaker than pereopods V; the 

 6th segment is teardrop shaped, tapering distally; the small claw has a 

 unique structure; it is falcate and forms with the process of the segment a 

 movable structure like a pair of tongs. Pereopods VII are slightly longer 

 but much weaker than pereopods VI. 



The uropods are rod-shaped and long. The telson is spatulate and 

 distally broadened. 



Distribution: The lone specimen was found in the equatorial Pacific 

 Ocean (7°36' N, 162°01' E) in a catch from 0-3,500 m. 



