402 The Ohio Naturalist. [Vol. VI, No. 2, 



Epistoma with anterior part triangular. Antenna! scale 

 rather broad, broadest in the middle. Flagellum longer than 

 carapace, but shorter than body. 



First pereiopod subcylindrical. Hand elongate, subcvlin- 

 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. 



Ischiopodites 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, 

 huiei sp^'c. „02' Male chicflv SO the hand, and the fingers are only 



sexual organ of left , . , -i , , ' , , °rT i i n 



side, inner view, slightly shortcr than the palm. Hand hardly 

 Enlarge . granulated, but with scattered hairs, more 



abundant than in the male. Pilosity of lower margin of meropo- 

 dite wanting. Annulns ventralis a simple, rounded, low tubercle 

 with an S-shaped fissure. 



Measurements: $ (Type): Total length: 35 mm.; carapace: 

 16, 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. ^905, 

 p. 96, and Ann. Carnegie Mus. 3. 1905 p. 437). The hooko v^f 

 the pereiopods and the subcylindrical chelae place it in the 

 section of C. blandingi. The shape of the rostrum and of areola 



