ISOPODS OF NORTH AMERICA. 



113 



sul)cqu!il :iMd each i.s about twice u.s lono- as the third. The tiag'cUuni is 

 composed of thirty-two articles. The second pair of antennae extend 

 to the fourth thoracic seg-inent. The inaxilliped is composed of seven 

 articles. The palp of the mandibles is composed of three articles. 

 The frontal lamina is broad and 

 has th(» anterior maroin trian- 

 guhirly produced, the apex be- 

 ing rounded and meeting* the 

 anterioi' })<)rti()n of the median 

 point of the front of the head. 



The first thoracic segment 

 is twice as long as any of the 

 other segments, which are su))- 

 eqnal. The epimera are dis- 

 tinct on all the segments with 

 the exception of the first. The 

 last four are crossed b}' an ob- 

 lique carina, the first two l)y a 

 longitudinal carina. The last 

 four are also broader than the 

 first two and have the outer 

 posthitei"al angle more acute, 

 it being produced in the last 

 two ])eyond the posterior mar- 

 gin of the segments. 



The first segment of the ab- 

 domen is entirely concealed 

 by the seventh thoracic seg- 

 ment. The sixth or terminal 

 segment is produced in a 

 rounded extremity, which is 

 crenulate and furnished with 

 eight spines. The inner branch 

 of the uropoda is wide and is 

 produced beyond the extremity 

 of the abdomen; its posterior 

 end is obliquel}' truncate, and 

 crenulate with the outer post- 

 lateral angle acutely produced 



in two prominent teeth; the outer margin is faintlv crenulate; both 

 margins are furnished with spines. The outer branch is half as wide 

 as the imuM- branch, is somewhat shorter, and is acutely produced in 

 two prominent teeth. The peduncle extends to the inner post-lateral 

 angle of the inner branch. 

 28589—05 8 



Fig. 95.— Cirolana pakva (.\ftkr Moore), a, Gen- 

 eral KiGURE. X 53. b, First antenna, x 33. 

 c. Second antenna, x 33. 



