574 



basipodite. The telson has a rounded tip and is less in length than its 

 width at the base and also the length of the last urosomite. 



Distribution: Known from the Pacific Ocean (Kuroshio) and the Red 

 Sea. It lives in the surface water layer. 



5. Amphithyrus sculpturatus Claus, 1879 (Fig. 250) 



Claus, 1879b: 16.— orientalis Stebbing, 1888: 1485; Shoemaker, 

 1925: 58. 



Length of adult females up to 5 mm, of males up to 3.5 mm. 



Unlike other species of the genus, not only the surface of all the body 

 somites has a reticulate sculpture, but even the surface of all the segments 

 of pereopods V, the 2nd segment of pereopods VI, and the uropods. 



The 2nd segment of pereopods I and II is equal in length to the dis- 

 tal segments together; in pereopods II the 4th segment is more broadened 

 than in pereopods I; in both pereopods I and II the distal processes fall 

 short of the base of the denticle of the 6th segment. The 2nd segment of 

 pereopods V is much shorter than the distal segments together. The 4th 

 segment of pereopods VI is 1 .5 times longer than the 5th, its distal pro- 

 cess short; the 5th segment has weakly bulged margins and lacks a distal 

 process; the 6th segment is 1/3 or less the length of the 5th, straight, 

 with parallel margins. Pereopods VII consist of a smoothly bent forward 

 2nd segment and three-five rudimentary distal segments. 



'463 



Fig. 250. Amphithyrus sculpturatus Claus, male 



