513 



the elongation of the rostrum, in males slightly less than 1/3 the body 

 length. The rostrum is denticulate along the lower margin, somewhat 

 shorter than the proximal part of the head occupied by the eyes, and the 

 transition from head to rostrum is smooth; the maximum height of the 

 head occurs at the place of its articulation with the pereon. 



The pereon somites are less in height than the head; the first somites 

 and last ones differ little in size. The 2nd segment of pereopods I has 

 a bulged anterior margin and an alinost straight posterior one, and its 

 length is somewhat more than the total length of the 3rd-5th segments; 

 the 5th segment is distally broadened, its maximum width about equal 

 to its length, and the posterior distal angle is denticulate and armed with 

 setae; the 6th segment has a strongly bulged anterior margin, the dis- 

 tal part of which forms an acute projection extending beyond the base 

 of the claw; the posterior margin is straight and finely denticulate and 

 the surface of the segment bears setae. The structure of pereopods II 

 of sexually mature females is characteristic of the species: in the 2nd 

 segment the distal part of the posterior margin is highly extended and 

 forms an acute triangular projection, which in young females and males 

 415 is poorly developed; the 5th segment has a straight posterior margin, 

 a barely bulged anterior margin, is distally slightly broadened, and its 

 maximum width is approximately equal to the length of its anterior mar- 

 gin. But if the 5th and 6th segments of pereopods I form a subchela, the 

 strong distal tooth of the 5th segment of pereopods II together with the 

 denticulate posterior margin of the 6th segment forms a well-developed 

 chela which is denticulate adjacent to the marginal tooth; the posterior 

 distal part of the 5th segment as well as the surface of the 6th segment 

 bears fine setae; the 6th segment has a uniformly bulged anterior mar- 

 gin and a straight posterior one; the claw is equal to half the length of 

 the 6th segment. Pereopods III-IV are thin, especially pereopods IV; the 

 2nd segment has a bulged posterior margin, a weakly concave anterior 

 margin, and is somewhat longer than the 3rd-4th segments together; the 

 4th and 5th segments are equal in length, the 6th is somewhat longer; the 

 4th-6th segments bear fine setae on the posterior margin. Pereopods V 

 have a spiniform process at the base of the 2nd segment; the 2nd seg- 

 ment is less than the total length of the remaining segments, its anterior 

 margin straight or barely concave and denticulate, the distal part pro- 

 jecting in the form of a denticle, and the posterior margin uniformly 

 bulged; the 4th-6th segments are narrow and bear fine setae along the 

 anterior margin. The 2nd segment of pereopods VI is just barely longer 

 than the rest of the leg, proximally strongly broadened, and its posterior 

 margin forms a roundish lobe that projects proximally over the place of 

 articulation of the segment; distally this margin is also strongly bulged 

 as an acutely angled projection extending far beyond the base of the 4th 



