CAMBARUS. 103 
43. Cambarus Palmeri. 
Plate III, fig. 6, Plate X. figs. 5a, 5a. 
Cambarus Palmeri, Faxon, Proc. Amer. Acad. Arts and Sei., XX. 124, 1884. 
Male, form II.— Rostrum broad, subexcavated, margins nearly paral- 
lel from base to lateral spines, which are small and sharp; acumen long. 
Post-orbital ridge with sharp anterior spine. Carapace smooth and pune- 
tate above, granulate on sides, lateral spine of moderate size, anterior lateral 
border notched just below the sub-orbital angle, which is not prominent. 
Areola linear for a short distance anterior to the centre, with a small ante- 
rior and a larger posterior triangular field. The length of the areola is 
one half the distance from cervical groove to tip of rostrum. Abdomen as 
long as the cephalothorax. Proximal segment of telson bispinose on each 
side. Antenne nearly as long as the body. Lamina a trifle longer than 
rostrum, broad, greatest width at the middle, thence tapering to the long 
spine at apex. Third maxillipeds hairy within and below. Anterior process 
of epistoma truncate at apex. Chela broad, depressed, smooth and punc- 
tate below, ciliate-punctate above, margined on the outer edge. Inner mar- 
gin of hand short, with a double row of small ciliated tubercles. Fingers of 
moderate length, straight, corneous and incurved at tip, costate, punctate, and 
ciliate above. Movable finger with outer edge furnished with a double row 
of ciliated tubercles on basal half. Outer finger hairy below at base of inner 
side. Carpus tuberculate above, with a strong and acute internal median 
spine, and a minute one at the base; smooth below, with two prominent 
anterior spines. Third pair of legs hooked. First pair of abdominal ap- 
pendages articulated near the base, long, stout, strongly curved, bifid for a 
short distance from tip, rami divergent, outer one the longer. 
Female. — Annulus ventralis triangular, rounded anteriorly, posterior 
wall with a longitudinal sigmoid fissure. Sternum between fourth pair of 
legs smooth. 
Length, 61 mm. Antenne, 52 mm. 
Twenty-five specimens of this species were collected for the U. 8. Na- 
tional Museum by Mr. Edward Palmer, in a brook running into the eastern 
side of Red Foot Lake, near Idlewild Hotel, Obion Co., Tenn., May 30, 1882. 
The lot contains males of the second form and females. The rostrum, chel, 
and antennal scale are similar to those of C. virilis. It differs from that 
