620 NORTH AMERICAN ASTACID.E FAXON. 



Id an individual 78 mm long the chela measures 25 by 9.5 mm , while in a 

 male 71 mm long the chela is 35 by 9 mtn . The annulus ventralis forms a 

 prominent tubercle. The rostrum is subdenticulate near the apex. 



Cambarus evermanni, sp. nov. 



Male, form I. — Rostrum broad, triangular, smooth, moderately con- 

 cave above, margins raised into sharp crests which extend well back on 

 the carapace between the post-orbital ridges ; no lateral spines. Post- 

 orbital ridges without spines. Carapace compressed laterally, fore 

 border hardly angulated below the eye; punctate above, granulate on 

 the sides, no lateral spine, branchiostegian spine small ; distance from 

 the cervical groove to the hind border of the carapace scarcely 

 one-third the length of the whole carapace ; areola of moderate 

 width. Abdomen longer than the cephalothorax ; two spines on 

 each side of the hind border of the basal segment of the telson ; term- 

 inal segment of the telson shorter than the basal. Anterior process of 

 the epistoma subtruncate. Basal segment of the antennule furnished 

 with a spine on the inner margin of the ventral surface half way 

 between the proximal and distal extremities. Antenna? shorter than 

 the body, spines on the second and third segments obsolescent; anten- 

 nal scale broad, broadest in the middle, surpassing the rostrum and 

 equaling the peduucle of the antenna. Third pair of maxillipeds 

 setose within and below. Chelipeds slender ; chela long, subcylindrical, 

 squamoso-tuberculate, inner border provided with a row of about 

 seven dentiform tubercles ; fingers as long as the hand, straight, with 

 longitudinal ribs ; carpus tuberculate on the inner side, armed with one 

 prominent spine on the inner border; meros tuberculate on the upper 

 margin, with two rows of spines below. Third and fourth pairs of 

 legs hooked on the third segment ; hooks of both pairs simple. 

 Fourth and fifth pairs of legs with a flattened, laminate tubercle on 

 the basal segment, that on the fourth pair the larger. Anterior abdom- 

 inal appendages of moderate length, somewhat recurved at the end, 

 outer part terminating in a horny truncate head with a slightly 

 developed recurved tooth, beared anteriorly on the outer side; inner 

 part terminating in an articulated spine obliquely placed, and not 

 exceeding the outer part of the appendage. 



Length, 70 mm ; from tip of the rostrum to the cervical groove, 22 mm ; 

 from the cervical groove to the posterior margin of the carapace, 10 mm ; 

 abdomen, 37 mm ; cheliped, 65 mm ; chela, 33 by 7 mm ; width of areola in 

 its narrowest part, 2 mm . 



Escambia River at Flomaton, above Pensacola, Florida. D. S. Jor- 

 dan, B. W. Evermanu, and C. H. Bollman (M. C. Z.). 



This species belongs to group I, (type, C. blandingii). It is nearly 

 related to G. alleni Fax. but differs in the form of the first pair of ab- 

 dominal appendages (c/. the description of those parts in G. alleni, 

 Rev. Astacidse, p. 35), in the simple structure of the hooks of the fourth 



