550 



slightly shorter. The basipodite of uropods II is still shorter; the exopodite 

 is much smaller than the endopodite; the rami have smooth margins and 

 their tips are stretched into a cusp. The basipodite of uropods III is fused 

 with the endopodite, rarely indistinctly separated; the endopodite is about 

 1.5 times as long as the exopodite and its margins finely denticulate; the 

 exopodite has a smooth anterior margin; both rami have a straight anterior 

 margin and a bulged posterior one. 



Distribution: Known from the Atlantic (northern tropical part), . 

 Indian (Zanzibar), and Pacific (Kuroshio, region of Chile-Peru, New 

 Zealand) oceans. It lives in surface water layers but may be found to 

 depths of 500-800 m. 



3. Platyscelus serratulus Stebbing, 1888 (Fig. 237) 



Stebbing, 1888: 1470; Chevreux and Page, 1925; All.—dubius 

 Shoemaker, 1925: 5\.—serratus Claus, 1879b: 11 (Eutyphis); 1887: 37 

 (Eutyphis). 



Length of adult specimens 6-7 mm. 



The body is high and compact but the abdomen is generally not 

 tucked under the pereon. The head is more than twice higher than long, 

 anteriorly rounded, and ventrally terminates in a beak-shaped process 

 that is much smaller than in the preceding species. In antennae II of 

 males the two distal segment of the flagellum are only slightly shorter 

 than half the length of the proximal segments. 



The 2nd segment of pereopods I is relatively short and the anterior 

 margin more bulged than the posterior one, and bears a few marginal 

 setae; the distal segments together are equal to the 2nd in length or 

 longer; the 4th segment is wider than its length; the 5th segment without 

 the distal projection is also wider than its length; the distal projection 

 has straight denticulate margins and its tip does not reach the tip of the 

 6th segment; the 6th segment has a smooth anterior margin. The 2nd 

 segment of pereopods II has an almost straight anterior margin and a 

 bulged posterior one; the 4th segment is far less broadened distally than 

 in pereopods I; the distal process of the 5th segment is long and narrow 

 and its tip reaches the base of the claw. Pereopods V are the same as in 

 the preceding species. The 2nd segment of pereopods VI has a concave 

 anterior margin, while the posterior margin is bulged in the proximal part 

 and almost straight in the distal. The 2nd segment of pereopods VII is 

 curved forward, the two small distal segments are bent backward. 



The uropods and telson are similar to those in P. armatus. 



Distribution: Known from the Mediterranean and Red seas, and the 

 Atlantic (south of 50° N), Indian (Zanzibar, Bay of Bengal), and Pacific 

 (Kuroshio, southeastern part, equatorial zone, region of New Zealand) 

 oceans. 



