394 MEMOIRS OF THE CARNEGIE MUSEUM 
5. CamBarus (Bartrontus) cARoLINUS Erichson. 
(Plate A, Fig. 4; Plate XX XIX, Fig. 3a and 3d, and 9; Plate XL, Fig. 4). 
Astacus (Cambarus) carolinus Erichson, 1846, p. 96. 
Cambarus dubius Faxon, 18846, p. 114; Faxon, 1885a, p. 70, Pl. 4, f. 3, Pl. 8, f. 7; Underwood, 1886, p. 368 ; Faxon, 
1890, p. 624; Hay, 1899, p. 959, 965. 
Cambarus carolinus Hay, 19026, p. 38; Ortmann, 1905a, p. 393. 
Cambarus ( Bartonius) carolinus Ortmann, 1905b, p 120, 135. 
Body robust, smooth, except for short hairs, chiefly. on the chel in freshly 
moulted individuals. 
Carapace subovate, not depressed, but rather compressed in comparison with the 
species described above. G:H:B=1:1.07 to 1.1:1.1, that is to say, the vertical 
diameter and the transverse diameters of the hepatic and branchial regions are 
practically the same, the two transverse diameters being only slightly greater than 
the vertical. The greatest width of the branchial regions is well forward, immedi- 
ately behind the cervical groove. 
Cervical groove deep, not interrupted on the sides. 
Areola distinctly longer than half of the anterior section of the carapace 
(a:p =1:1.65 to 1.74), very narrow (w:! = 1:10 to 15), with only one, or rarely 
two, very irregular rows of punctures, which occasionally are almost entirely lacking. 
Rostrum (Pl. XX XIX, Fig. 3a and 36) slightly curved downward toward the 
tip, broad and short, never reaching beyond the distal end of the second joint of 
the peduncle of the antennula, but generally only to the middle of it, being some- 
times even shorter than that. Upper surface slightly concave, with elevated mar- 
gins. Margins straight, sub-parallel, or slightly converging: toward the tip, sud- 
denly contracted into a broad, short, triangular acumen. Basal angles of acumen 
rather sharp, but without any trace of marginal spines. These angles are empha- 
sized by the sudden disappearance of the slight swelling of the lateral margins, 
which are not at all swollen on the acumen. Acumen pointed, but point short. 
Postorbital ridges short, almost parallel, ending bluntly anteriorly. 
Surface of carapace punctate, granulated only on the hepatic region, and some- 
times with a few indistinct granules immediately behind the cervical groove on the 
branchial region. No lateral spine. External orbital angle rarely or not at all 
marked, generally formed by a rounded or slightly angular, insignificant projection, 
but never with a spine. Branchiostegal spine formed by a small, often indistinct, 
tubercle. 
Abdomen always distinctly shorter than the carapace, narrower than the latter 
in the male, almost as wide as the carapace in the female. Anterior section of telson 
