ISO PODS OF NORTH AMERICA. 



141 



are somewhat hirsute. 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 posteriorly trun- 

 cate with the lateral angles rounded; it is as long as the terminal 

 segment of the body. The outer branch is less than half as wide as 

 the inner branch, is produced to a narrowly rounded extremity, and 

 is as long as the outer branch. The inner angle of the peduncle 

 extends a little beyond the lateral incisions of the terminal abdominal 

 segment. 



FlG. 121. EXOCORALLANA TRICORNIS (AFTER HANSEN). a, LEFT LEG OF FIFTH PAIR OF MALE. 6, LEFT 

 LEG OF SECOND PAIR OF MALE. C, LEFT LEG OF SEVENTH PAIR OF MALE. (I, INNER PARTS OF MOUTH, 

 FROM BELOW, e, INNER PARTS OF MOUTH (PARAGNATHIA OMITTED). /, FIRST ANTENNA OF FEMALE. 



<j, MIDDLE PART OF LEFT MAXILLIPED OF MALE, h, 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, t, 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. 



<7, LEFT PLEOPOD OF ADULT MALE (SECOND PAIR) . r, POSTERIOR PART OF ABDOMEN OF ADULT MALE. 

 S, DISTAL PART OF LEFT MANDIBLE, t, ADULT FEMALE. M, DISTAL PART OF LEFT MANDIBLE. V, RIGHT 

 MANDIBLE. (ENLARGED.) 



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

 ambulatory. 



In the female 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 differ from the specimens 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 occidental/is. 



