CAMBARUS. 119 
inner shorter, incurved, and a little dilated before the tip; a projecting angle 
or shoulder on the anterior border at base of rami. 
Male, form II. — Chela smaller, fingers not gaping, hook on third segment 
of third pair of legs smaller; first pair of abdominal appendages split only 
half as far down as in the first form, rami much thicker, no projecting angle 
on the anterior border; these appendages are as long as in the first form, 
reaching forward to the base of the chelipeds; they are articulated near 
the base. 
Female. — Chela shorter and wider, external finger bearded within at 
base ; sternum between fourth pair of legs non-tuberculate, lightly ciliate. 
Annulus ventralis large, transverse fossa broad and deep, anterior border 
bituberculate. 
Measurements of a male, form I.— Length of body, 73 mm. Length of 
carapace, 36 mm. From tip of rostrum to cervical groove, 24 mm. From 
cervical groove to hind border of carapace, 12 mm. Length of rostrum, 
11mm. Breadth of rostrum at base, 4.5 mm. Length of acumen of rostrum, 
4mm. Width of areola, 2.6 mm, Length of abdomen, 57 mm. Length of 
chela, 34mm. Breadth of chela, 14 mm. Length of movable finger, 22 mm. 
Known Localities. — Kentucky: Grayson Springs, Grayson Co.; Green 
River, near Mammoth Cave; Cumberland Gap. 
M. C. Z.. No. 3574 (young female), from Knoxville, Tenn., Walter 
Faxon, and No, 3575 (male, form I.), from Bradford, Ind., A. S. Packard, 
Jr., probably belong to this species, but the specimens are too young to 
determine with confidence. 
This species resembles C. spixosus, from which it is easily distinguished 
by the length of the posterior section of the carapace, and by the length of 
the male appendages. From C. affnis it may be separated by the different 
form of the male appendages and female annulus ventralis, and by the single 
lateral spine of the carapace. I have seen males of the first form only 
34 mm. in length. 
50. Cambarus forceps. 
Plate V, fig. 4, Plate IX. figs. 5, 5/, Ba, Sal. 
Cambarus forceps, Faxon, Proc. Amer. Acad. Arts and Sci., XX. 133, 1884. 
Male, form I. — Rostrum narrow, excavated, faintly carinated in the mid- 
dle; margins divergent at the base, thickened, dotted-lined; acumen long 
