ISOPOD8 OF NORTH AMERICA. 



211 



FIG. 213. ROCIXELA ARIES (AFTER 

 SCHICEDTE AND MEINERT). , 

 FRONTAL MARGIN, ANTENN.K AND 

 FRONTAL LAMINA. 6, ADULT 

 FEMALE. (ENLARGED.) 



the fourth is a little longer than the third; the fifth is one and a half 

 times longer than the fourth. The flagellum is composed of twelve 

 articles. The second antennae extend to the posterior margin of the 



second thoracic segment. The frontal 

 lamina is small and almost inconspicuous, 

 triangular in shape at the base, which is 

 ventrall} T placed. The maxilliped has a 

 palp of two articles. 



The first, fourth, fifth, and sixth seg- 

 ments of the thorax are a little longer 

 than the others. The epimera are distinct 

 on all the segments but the first. They 

 are narrow plates with the posterior an- 

 gles increasingly acute. The epimera of 

 the last segment are produced beyond the 

 posterior margin of the segment. 



The first segment of 

 the abdomen is almost 

 entirety concealed by 

 the last thoracic seg- 

 ment. The lateral 

 parts are not sepa- 

 rated from the dorsal portion. The sixth or ter- 

 minal segment is rounded posteriori. The base 



of the terminal seg- 

 ment is marked with 

 three longitudinal 

 black lines, one on 

 either side of a me- 

 dian line, and two 

 oblique lines, one on either side, and all five 

 connected at the base. The outer branch 

 of the uropoda is shorter than the inner 

 branch and half as wide. The inner branch 

 is obliquely truncate, with rounded an- 

 gles. The outer branch is posteriorly 

 rounded. The peduncle of the uropoda is 

 as long as the outer branch. The margins 

 of the uropoda and the terminal segment are furnished with spines. 



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

 latory. The merus of all three anterior legs is furnished with two 

 spines, the carpus with one spine, and the propodus of the second and 

 third with one spine. The ambulatory legs are beset with a few spines. a 



a For description of the young of the first stage, see Schicedte and Meinert, Nat. 

 Tidsskr. (3), XII, 1879-80, pp. 402-403. 



FIG. 214. ROCINELA ARIES 

 (AFTER SCHICEDTE AND 

 MEINERT). YOUNG. (EN- 

 LARGED.) 



FIG. 215. ROCINELA ARIES, , MAX- 

 ILLIPED. x 3f . 6, LEG OF SECOND 

 PAIR, x Hi. 



