160 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



with complete rows becoming- successively more dense posteriorly. In 

 one specimen a very few hairs at side of second segment. First three 

 pairs of per^eopods subsimilar, fourth joint broad and armed with sev- 

 eral very strong spines, fifth joint very short, alniost hidden in the 

 first leg, somewhat longer in the second and still longer in the third. 

 Seventh joint pectinate, with four long spines in the first leg, in the 

 second and third legs these becoming weaker. Claws strong in all. 



"Last four legs successively longer and relatively to their length 

 more slender than the first three pairs, heavily armed with numerous 

 brown-tipped spines. 



Fl(i. 140.— Al.CIRONA HIRSl'TA (AFTER MOORE). ((, RIGHT SIDE OF TERMINAL ABDOMINAL SEGMENT 



WITH iiRopoD. b, Seventh leg. x 40. c. General figure, x 8. d, First leg. x 40. c, Fourth 

 LEG. x 40. 



"Pleon of five visible segments, dorsally strongly setose, first and 

 second segments narrow and laterally covered by the seventh thoracic 

 segment, the first being visible only dorsally; third segment posteri- 

 orly produced at the sides, covering the lateral portion of the fourth 

 segment, which is the longest in the median line. This region is so 

 setose that it is difiicult to delimitate the segments. 



"Telson trianguUir, with the tip rounded and armed with six spines, 

 about two-thirds as long as l)road; dorsal surface and posterior mar- 

 gin with numerous setie. Uropods extending somewhat beyond end 

 of telson, inner V)ranch the longer, not much longer than broad, 

 rounded, with about ten marginal spines and numerous setie about 



