Pomona Coi.leok .loniNAi. ok Entomoi.ooy 573 



to that in Asellus communis. The body is much h)nger and the segments of the 

 thornx are much more loosely nrtieiilated than in .hcllii.s communis. The trniiinal 

 abdominal segments and the uropoda are also much longer and narrower than in 

 ,lscllu.<i communis. 



This Isopod is evidently not allii-d to either Caccidoiea richardsonae or to 

 Caecidotea smithsii since the propodus of the first leg is armed with triangulnr 

 processes. It falls much nearer to ('. stygia and C. nickajackrnsis. It differs 

 from C. nichajackensis in having the first pair of legs armed with two triangular 

 processes instead of with one triangular process at the distal end and one spine 

 at the proximal extremity; also in the length of the urojioda, which arc shorter 

 than the abdominal segment in C nickajackcii.ii.i. It is therefore most closely 

 allied to C. slygia. But it differs from C stygia in having the propodus of the 

 first leg armed with two large triangular processes only, and three spines whereas 

 C. siypia has two large and three small triangular processes and no s])ines. The 

 uropoda of this Isopod, C. alahamcnsis, are somewhat longer than the terminal 

 abdominal segment. The outer branch of the uropoda is half as long as the inner 

 branch whereas in C. slygin the outer is two-thirds as long as the inner. 



In C. slygia the first two articles of the first antenna' arc subequal in length 

 but in C alabamensis the second is longer than the first. In the former the 

 flagellum of the first antenna- has twelve articles, in the latter it has but ten 

 articles. In C. stygia only five articles are given for the peduncle of the second 

 antennw whereas this Isopod appears to have six, four small articles instead of 

 three, although this may be merely a difference in observation. The flagellum of 

 the see<ind aiitcnnie of C. alabamensis has about eighty-five articles; that of C. 

 ttypia has but seventy. The terminal abdominal segment of C. ttygia is less 

 elongated than that of C. alabamensis, one and one-half times as long as wide in 

 the former, once and two-thirds as long as wide in the latter. In ('. slygia the 

 median terminal lobe is less prominent than in C. alabamenii*. 



