570 



459 The basipodite of uropods II is somewhat shorter than the rami. 

 The endopodite of uropods III is fused with the basipodite. The telson 

 is triangular, with a pointed tip, its margin either sHghtly concave or 

 straight, and its length 1.5-2 times its width. In some individuals the 

 telson may be indistinctly separated from the urosome. 



Distribution: A warm-water, circumoceanic species known from the 

 Atlantic (south of 43° N), Indian (Bay of Bengal), and Pacific (South 

 China Sea, Kuroshio, eastern tropical part) oceans, and the Mediterranean 

 Sea. It inhabits the upper 2(X)-300 m layer but is found more often in 

 the warmed surface layer. 



460 2. Amphithyrus similis Claus, 1 879 (Fig. 247) 



Claus, 1879b: 16; 1887: 42; Spandl, 1924: 39.— bispinosus Spandl, 

 1927: 247 (similis var.). 



Length of adult individuals about 3 mm. 



In external appearance and structure of the body sections and 

 extremities, this species is close to A. bispinosus. Based on the 

 similarity in structure of pereopods VI (shape of 2nd segment and lateral 

 fissure), pereopods VII (consisting of one basal segment), and the telson 

 (with pointed tip), Spandl (1927) considered A. similis a variety of 

 A. bispinosus, bearing in mind that coxal plate V is not modified into 

 a spine. However, a comparison of the description and drawings of both 

 species revealed significant differences; the major ones are listed on the 

 following page. 



460 



Fig. 247. Amphithyrus similis Claus, female (after Claus, 1887). 



