ISOI'ODS OK NORTH AMKRTOA. 



141 



arc somewhat hirsuto. A little more than half way between the base 

 and the apex of the segment the lateral margin is incised on either 

 side. The inner branch of the uropoda is broad and })osterioily trun- 

 cate with the latei'al ano-los rounded; it is as loiio- as the termin:d 

 seo-mcnt of the body. The outer branch is less than halt as wide jis 

 the iinier branch, is produced to a nari'owly rounded extremity, and 

 is as long' as the outer branch. The inner angle of the j)e(luncle 

 (^xtends a little beyond the lateral incisions of the terminal ab(h)minal 

 se anient. 



Fig. 121.— Exocorai.lana tricornis (After Hansen), a, Left leg ok fifth pair of male, b, Left 



LEG OF second PAIR OF MALE. C, LEFT LEG OF SEVENTH PAIR OF MALE. </, INNER PARTS OF MOUTH, 



from below. c, inner parts of mouth (paragnathia omitted). /, first antenna of female. 

 .'/. Middle part of left maxilliped of male. /;, Basal part of flagellum of second antenna 

 OF male. /, Lateral view of male, j, Left maxilla of second pair of male, k, Left mandible 

 OF MALE. /. Left maxilla of first pair, m, Ventral view of head of female, n. Head of 



ADULT male (dorsal VIEW). O, LEFT MAXILLIPED OF FEMALE, p, LEFT MAXILLIPED OF MALE. 



(/, Left pleopod of adult male (second pair). ?■, Posterior part of abdomen of adult male. 

 s. Distal part of left mandible, t, Adult female, u, Distal part of left mandible, v. Right 

 mandible. (Enlarged.) 



The tiist three pairs of legs are prehensile, the last four pairs 

 ambulatory. 



In the feuiale the tubercles on the head are smaller and less promi- 

 nent, as well as the median frontal process. 



Three specimens, a male and two females are from the Gulf of Cali- 

 fornia. They ditl'er from the spechiiens of the East coast only in hav- 

 ing larger tubercles on the abdominal segments on either side of the 

 median longitudinal groove. This new subspecies may be known as 

 tricornis occidentalln. 



