I2 6 CRUSTACEA MAI,AC( ISTRACA. II 



Thoracic segments, seen from above (fig. 5 a), in the main as in P.subfi/is, but more tapering 

 than in this species; the lateral margins are sharply angular; second segment is unusually long, only 

 a little shorter than the third, which is as long as the fourth or the fifth. — Second and third pairs 

 of thoracic legs (fig. 5 b) somewhat long and slender, with the spines thin and moderately or very 

 short; fifth joint conspicuously longer than the fourth; sixth joint only a little shorter than fourth 

 and fifth joints combined and considerably longer than the seventh joint with claw. Three posterior 

 pairs (fig. 5c) only a little shorter than second pair; second joint is clavate, being very thin towards 

 the base while the distal part is thick; sixth joint is somewhat longer and considerably thinner than 

 the robust fifth joint and somewhat longer than the seventh joint with claw. 



Abdomen in general shape somewhat similar to that of P. subtilis. As the seventh thoracic 

 segment is only half developed -- having no legs -- in the juvenile specimen shown in fig. 5a, the 

 length of the abdomen must in this figure be compared not with seventh but with sixth thoracic 

 segment. In the immature male (fig. 5 c) the five anterior segments combined are nearly half as long 

 again as seventh thoracic segment; the pleopods are of moderate size, with the exopod longer than 

 the peduncle, but both rami completely without seta;. In the immature male the sixth abdominal 

 segment is not quite as long as the three preceding segments combined; in the juvenile specimen it 

 is even longer than the four preceding segments combined; it is a little less broad in proportion to 

 length than in P. subtilis, and the produced part between the uropods is not triangular but rounded. 

 Uropods considerably shorter than the sixth segment; the peduncle is much shorter than deep 

 (fig. 5c); the endopod two-jointed, with the second joint much longer than the first; the exopod is 

 well marked off, one-jointed, a little more than half as long as, and much thinner than, the endopod. 



Length of the immature male 2.15 mm , of the juvenile specimen 1.7 mm . 



Remarks. In the structure of the uropods and the posterior protuberance on the basal joint 

 of the chelipeds P. ckevipes is sharply distinguished from the two preceding species. The clavate shape 

 of the second joint of the three posterior pairs of thoracic legs is also very characteristic. 



Occurrence. Taken by the "Ingolf" at the deepest of its stations. 



South of the Davis Strait: St. 38: Lat. 59 12' N., Long. 51 05' W., 1870 fm., temp. 1.3 ; 2 spec. 



(1 immature male and 1 juvenile specimen). 



