648 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xx. 



GROUP II. (Type, Astacus advena Le Conte.) 



Third segment of third pair of legs of male hooked. First pair of 

 abdominal appendages of male similar to those of Group 1. 



CAMBARUS CARINATUS, new species. 

 (Plate LXIII.) 



Male, Form I. — Rostrum of moderate width, excavated, lateral margins 

 slightly convergent, carinated, and armed near the tip with a pair of 

 spiniform teeth ; acumen of moderate length, reaching to the distal end 

 of the antennular peduncle; a median longitudinal carina extends from 

 the base of the acumen backward to the level of the eyes. Carapace 

 coarsely granulated on the sides, armed with a pair of lateral teeth 

 behind the cervical groove; branckiostegian spine small; postorbital 

 ridges furnished with sharp anterior spines, posterior spines repre- 

 sented by slight tubercles ; anterior border of caraj)ace angulated below 

 the orbit. Areola of moderate width, about one-half the length of the 

 anterior section of the carapace. 



Abdomen equal to the cephalo-thorax in length, smooth; pleurae 

 broad, bluntly angled. Anterior segment of telson three-spined on 

 each side of the posterior margin; posterior segment short, rounded. 



Basal segment of antennule armed with a spine below. Antennal 

 scale broadest at the middle, tapering to a sharp apical spine. A sharp 

 tooth at external base of the antennal scale. Epistoma triangular. 



Chelipeds: Merus granulated on superior border, and armed with a 

 single spine near the distal end; lower face with biserial arrangement 

 of spines; carpus tuberculate within, with four spiniform teeth near 

 the anterior border, viz, one near each point of articulation with the 

 propodite and two between these points; hand of moderate width, 

 inflated, covered with small squamous tubercles. 



Third segment of third legs hooked. 



First abdominal appendages stout, curved forward at apex, inner and 

 outer parts ending in a small horny tooth, anterior margin furnished 

 with a small tooth near the tip. 



Length 125 mm.; carapace 62 mm.; length from tip of rostrum to 

 cervical groove 40 mm.; length of rostrum from tip to anterior spine 

 of postorbital ridge 17 mm.; acumen 5 mm.; cheliped 104 mm. (merus 

 25 mm., carpus 16 mm., chela 51 mm., dactylus 30 mm.); breadth of 

 chela 17 mm. 



Type.— Guadalajara, Mexico, altitude 5,200 feet (No. 17699, U.S.N.M.), 

 P. L. Jouy. One inale, Form I. 



Ameca, Jalisco, Mexico (No. 16085, U.S.N.M.), A. Duges. Hacienda 

 de Villachuato, Michoacan, Mexico (No. 17707, U.S.N.M.), A. Duges. 

 Three males, Form I. 



According to the manuscript label this species is brought to the 

 market of Guadalajara as food. 



