OP ARTS AND SCIENCES. 109 



on the second and third pairs of legs, the terminal teeth of the first 

 pair of abdominal legs smaller and not corneous. 



In the female the chelipeds are short, the chelae broad. Sternum 

 bituberculate between the fourth pair of legs. Annulus ventralis 

 umbilicoid, with a tubercle in the median depression. 



Length, 100 mm. Rostrum, 15 mm. ; acumen, 3 mm. Length 

 of carapace, 51 mm. From cervical groove to posterior margin of 

 carapace, 18.5 mm. Abdomen, 50 mm. Width of areola, 1.5 mm. 

 Chelipeds, 92 mm. Chela, 43 mm. 



Known localities. Mississippi : Macon, Artesia. 



Closely related to Cambarus Blandingii, but easily distinguished by 

 the first pair of abdominal legs of the male, which are characteristic 

 even in very small specimens. Over a dozen specimens of this spe- 

 cies (including males of the first form, males of the second form with 

 first pair of abdominal appendages articulated near the base, and un- 

 articulated, and females) were collected by Prof. O. P. Hay in East- 

 ern Mississippi. One lot has a particular locality specified, Macon. 

 Macon is situated on the Noxubee, an affluent of the Tombigbee River. 

 Another lot was collected at Artesia, a town about twenty miles 

 north of Macon. 



2. C. pubescens, sp. nov. 



Male, form II. Rostrum long, triangular, sides sub-parallel at the 

 base, then converging towards the lateral spines, which are evident ; 

 slightly depressed above at the base, subplane, with raised margins ; 

 eiliated especially on the acumen ; acumen long, pointed. Post- 

 orbital ridges with anterior spines. Carapace cylindrical, fore border 

 angulated behind the antennas, punctate above, slightly granulated 

 on the sides, with one lateral spine on each side. Cervical groove 

 ciliated. Cardiac region short (much less than one third as long as 

 the anterior part of the carapace) . Areola broad. Sternum covered 

 with a dense growth of coarse setae. Abdomen longer than the 

 cephalo-thorax. Proximal segment of telson armed on each side with 

 four spines. Anterior process of epistoma broad triangular with 

 ciliated margin. Basal segment of antennule with a sharp spine 

 below near the inner margin of the middle of its length. Antennae 

 shorter than the body. Second and third segments with acute exter- 

 nal spine ; scale a little longer than peduncle of antennas and rostrum, 

 moderately broad, broadest below the middle. Third maxillipeds 

 hairy within and below. Chela moderately broad, covered with in- 

 conspicuous ciliate squamous tubercles, internal margin nearly straight. 



