ISOPODS OF NORTH AMERICA.. 



437 



segment, about one-half its length. The peduncle is about as long as 

 the inner branch. The outer branch is about one-fourth shorter than 

 the inner branch. 



The first pair of legs are subchelate. The propodus is armed on the 

 inferior margin with a triangular process near the distal end and with 

 a long spine at the proximal extremity. The dactylus is armed with 

 numerous spines along the inferior margin. All the other legs are 

 ambulatory, with dactyli uni-unguiculate. 



C^ECIDOTEA RICHARDSON^E Hay. 



Ciecidotea richardsanie HAY, Proc. Biol. Soc. Washington, XIV, 1901, pp. 179-180; 

 Proc. U. S. Nat. Mus., XXV, 1903, pp. 424-428. 



Locality. Nickajack Cave, Tennessee. 



Bod} 7 narrow, elongate, four and a half times longer than wide, 2 

 mm. : 9 mm. 



Head a little wider than long, with the anterior margin slightly 

 excavate. Sides of head 

 entire. Eyes wanting. 

 The first pair of antennae 

 have the first article about 

 twice as long as wide; the 

 second article is as long as 

 the first, but half as wide; 

 the third article is one- 

 third the length of the sec- 

 ond; the flagellum is com- 

 posed of eleven articles 

 and extends one-third the 

 length of the fifth article 

 of the peduncle of the sec- 

 ond pair of antenna 1 . The 

 second pair of antenna? 

 have the first two articles 

 equal in length; the third 

 article is about half the 

 length of the second; the 

 fourth is as long as the 

 first three together; the 

 fifth is one and a half times 

 as long as the fourth. The 

 flagellum is composed of 

 about eighty-six articles. 



body. The maxillipeds have a palp of five articles, 

 mandibles is composed of three articles. 



The first four segments of the thorax are subequal in length. The 

 fifth is a little shorter. The sixth and seventh are subequal and each 



FIG. 495. C.ECIDOTKA RICHARDSON.E (AFTER HAY), a, DOR- 

 SAL VIEW, x 6. 6, FIRST ANTENNA, r, SECOND ANTENNA. 

 d, MANDIBLE, e, FIRST MAXILLA. /, SECOND MAXILLA. 

 y, MAXILLIPED. h. UPPER LIP. i, LOWER LIP. j, GNATH- 

 OPOD. 



The second antennne are longer than the 



The palp of the 



