402 
The Ohio Naturalist. 
[Vol. VI, No. 2, 
Epistoma with anterior part triangular. Antennal scale 
rather broad, broadest in the middle. Flagellum longer than 
carapace, but shorter than bodv. 
First pereiopod subcylindrical. Hand elongate, subcylin- 
drical, very slightly compressed, margins subparallel. Surface 
covered with fine granulations and a few short, scattered hairs. 
Palm long; fingers remarkably short, hardly over one-third as 
long as palm, with some scattered hairs. Cutting edges without 
tubercles. Carpopodite short, and almost smooth, without dis- 
tinct sulcus on upper side, and without spines or tubercles on 
inner side. Meropdite smooth, without tubercles or spines, its 
lower margin densely pilose. 
I schiopodites of third and fourth pereiopod with hooks, that 
of the third is long and strong, conical, that of the fourth is 
smaller, but distinct and of similar shape. Coxopodite of fourth 
pereiopod with a prominent, semicircular, compressed tubercle; 
that of the fifth pereiopod with a small, conical tubercle. 
First pleopod rather short and stout, reaching 
to the coxopodite of the third pereiopods. Its 
distal third is thinner than the proximal part, 
slightly tapering, gently but distinctly curved 
backward. Tip truncate, with two sharp, 
pointed, triangular horny teeth, belonging to 
the outer part. Inner part pointed at tip, point 
straight, slightly directed outward, distinctly 
longer than truncated part, and also longer than 
the horny teeth. Inner face of inner part with 
a row of beard-like hairs. 
The male of the second form is unknown. 
Fig. I. cambarus In the female, the chelipeds are much shorter, 
hineispec. vov. Male chieflv SO the hand, and the fingers are onlv 
side, inner view, slightly shorter than the palm. Hand hardly 
Enlarged. granulated, but with scattered hairs, more 
abundant than in the male. Pilosity of lower margin of meropo- 
dite wanting. Annulus ventralis a simple, rounded, low tubercle 
with an S-shaped fissure. 
Measurements: i (Type): Total length; 35 mm.; carapace: 
10, areola; 5. width of areola: 2.75; abdomen: 19 mm.; length of 
hand: 13 mm., width of hand: 3.5, length of palm: 9.5, of fingers: 
3.5 mm. 9 (Type): Total length: 45 mm.; carapace: 21, 
areola: 7, width of areola: 3.5, abdomen: 24 mm.; hand: 9.5 
palm: 5.5, fingers, 4 mm. 
The shape of the male organs places this species in the sub- 
genus Cambarus (see Ortmann, Pr. Amer. Philos. Soc. 44. 1905, 
p. 90, and Ann. Carnegie Mus. 3. 1905 p. 437). The hooks of 
the pereiopods and the subcylindrical chelae place it in the 
section of C. blandingi. The shape of the rostrum and of areola 
