394 MEMOIRS OF THE CARNEGIE MUSEUM 



5. Cambarus (Bartonius) carolinus Erichson. 

 (Plate A, Fig. 4 : Plate XXXIX, Fig. 3(/ and 3/^ and 9 ; Plate XL. Fig. 4). 



Astnciis {Catnbarus) carolitiiin Erichson, 1846, p. 96. 



Cambarus diibins Faxon, 18846, p. 114 ; Faxon, 1885fi, p. 70, PI. 4, f. 3, Fl. 8, f. 7 ; Underwood, 1886, p. 368 ; Faxon, 



1890, p. C24 ; Hay, 1899, p. 959, 965. 

 Cambarus carolinus Hay, 19026, p. 38; Ortniann, 1905n, p. 393. 

 Cambarus {Barfoiiius) ca ral i tiv s Ortmann, 19056, p 120, 135. 



B(jdj/ robust, smooth, except for short hairs, chietiy on the chelte in freshly 

 moulted individuals. 



Carapace sul)Ovate, not depressed, l>ut 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 <j move deep, not interrupted on the sides. 



Areola distinctly longer than half of the anterior section of the carapace 

 (a : p = I : 1.65 to 1.74), very narrow (v :l — 1 : 10 to 15), with only one. or rarely 

 two, veiy irregular rows of punctures, which occasionally are almost entirely lacking. 



Eostrurn (PL XXXIX, Fig. oa and 3//) 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 an}- trace of marginal spines. These angles are empha- 

 sized l)y the sudden disappearance of the slight swelling of the lateral margins, 

 which are not at all swollen on the acumen. Acumen pcjinted. but point short. 

 Postorbital ridges short, almost parallel, ending bluntly anteriorly. 



Surface of carapjace punctate, granulated only on the hepatic region, and some- 

 times with a few indistinct granules immediatelj' 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. Brancliiostegal 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 tehon 



