575 



The basipodite of uropods I is 1.5 times longer than the rami, in 



uropods II also longer than the rami. The endopodite of uropods III is 



464 fused with the basipodite or indistinctly separated from it. The telson 



has a rounded tip and its length is less than its width at the base and the 



length of the last urosomite. 



Distribution: Known from the Atlantic (south of 40° N), Indian 

 (eastern part), and Pacific (Kuroshio) oceans, and the Mediterranean and 

 Red stas. It inhabits the 0-100 m layer. 



XXIII. Family PARASCELIDAE Claus, 1879 



Small-sized (5-7 mm) animals. The body is broad, compact, and gen- 

 erally slightly flattened dorsoventrally. The pleon is generally narrower 

 than the pereon and, together with the urosome, may be tucked under 

 the belly. The head is short, broader than the pereon, and the anterior 

 margin rounded. The eyes are large and occupy almost the entire sur- 

 face of the head. However, the shape and proportions of the head and 

 body differ significantly in different genera. For instance, in Thyropus 

 and Parascelus the height of the head is more than its length and the 

 464 urosome and telson are tucked under the belly, while in Euscelus the 

 height of the head is less than or equal to its length and the body is 

 almost straight. Antennae II in females are short and few-segmented, in 

 males thin, long, and folded five times. The mouth parts are stretched 

 into a pointed cone. The mandibles are stretched, have a narrow cutting 

 edge, and the mandibular palp is present only in males. 



The coxal plates are free. Pereopods I and II are simple or ha>'e 

 chelae. The basal segment of pereopods V and VI is strongly broadened 

 and modified into an operculum, which in pereopods VI is always very 

 large; in pereopods V the distal segments are articulated subterminally, 

 and in pereopods VI more proximally. In pereopods VI the posterior 

 margin of the basal segments generally has a longitudinal "telsonic" 

 groove into which the edges of the uropods and the telson may be inserted 

 so that the body during rolling acquires an oval shape. Pereopods VII 

 generally (except for Thyropus) have a full complement of segments and 

 the distal segments together are slightly shorter than, equal to, or longer 

 than the basal segments. The endopodite of uropods II and III is fused 

 with the peduncle or may be separated. The broad telson is fused with 

 the last urosomite. 



The family includes five genera. 



KEY TO GENERA OF FAMILY PARASCELIDAE 



1 . Pereopods I and II simple 2. 



— Pereopods I and II with chelae 3. 



