620 NORTH AMERICAN ASTACIDE—FAXON. 
In an individual 78™™ long the chela measures 25 by 9.5™™, while in a 
male 71™™ long the chela is 35 by 9™™. The annulus ventralis forms a 
prominent tubercle. The rostrum is subdenticulate near tiie 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. Antenne 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 peduncle 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 
excceding the outer part of the appendage. 
Length, 70™" ; from tip of the rostrum to the cervical groove, 22™™ ; 
from the cervical groove to the posterior margin of the carapace, 10™™ ; 
abdomen, 37"™; cheliped, 65™™; chela, 33 by 7™™; width of areola in 
its narrowest part, 2™™. 
Escambia River at Flomaton, above Pensacola, Florida. D. 8. Jor- 
dan, B. W. Evermann, and C. H. Bollman (M. C. Z.). 
This species belongs to group I, (type, C. blandingii). It is nearly 
related to C. alleni Fax. but differs in the form of the first pair of ab- 
dominal appendages (cf. the description of those parts in C. alleni, 
Rey. Astacida, p. 35), in the simple structure of the hooks of the fourth 
