A NEW SUBTERRANEAN FRESHWATER 



ISOPOD 



BLANCHE E. STAFFORD 

 POMONA COLLEGE, CLAREMONT, CALIFORNIA 



These specimens of Caecidotea were found by Prof. C. F. Baker in the 

 waters of a well in Auburn, Alabama, and represent an interesting new species. 



Caecidotea alabamensis n. sp. 

 (Figures 189 and 190) 



The body without the antennae and the uropoda measures in length about 9 

 mm., in width about 1.50 mm. It is narrow and elongated, about si.x times as long 

 as wide. The head is wider than long and a little narrower than the first thoracic 

 segment. The anterior margin of the head is slightly excavate and distinctly 

 narrower than the posterior margin. The eyes are absent. 



The first pair of antennae has three basal articles and a flagellum. The 

 first article is about twice as long as wide. The second article is a little longer 

 than the first. The third is about two-thirds as long as the second and much 

 narrower. The flagellum has about ten articles. The second antennae have six 

 articles and a flagellum. The first four are small and about equal in size. The 

 fifth is as long as the first four and about three-fourths as long as the sixth. The 

 sixth is a little narrower than the fifth ; the flagellum has about eighty-five articles. 



The maxilliped has a palp of five articles, the mandible a palp of three 

 articles. 



The segments of the thorax are very loosely articulated and the lateral 

 margins of the segments are not contiguous. The second and third segments are 

 slightly shorter than the first. The fourth and fifth are shorter than the third. 

 The sixth and seventh are about equal to the second and third; they are more 

 loosely articulated than the other segments. The epimera of the first segments 

 are near the antero-lateral margin ; they are near the middle of the fourth segment 

 and on the last three segments they have a post-lateral position. 



The first two segments of the abdomen are short. The third is long and 

 narrow with a medial lobe on the posterior margin and is once and two-thirds as 

 long as wide. The uropoda are a little longer than the terminal abdominal seg- 

 ment. The peduncle is long and narrow, more than half as long as the abdominal 

 segment. The inner branch is two-thirds as long as the peduncle. The outer 

 branch is about one-half as long as the inner branch. 



The first pairof legs is sub-chelate, has propodus armed with two triangular 

 processes and three spines. The other legs are ambulatory. 



These specimens resemble Asellus in many features, very closely, and show 

 the close aftinity of Caecidotea to that genus. Tiie pleopoda are very similar to 

 those of Asellus communis. The second pair in the female is missing as also in 

 Asellus communis. The third, fourth and fifth pairs are more elongate and nar- 

 rower than those of Asellus. The form of tlie legs and mouth parts is also similar 



