ORTMANN: THE CRAWFISHES OF THE STATE OF PENNSYLVANIA On 
4. CampBarus (BARToNTIUS) BARTONI (Fabricius). 
Plate B, Fig. 1; Plate XX XIX, Fig. la-If, and Fig. 8; Plate XL, Fig. 2.) 
Astacus bartoni Fabricius, 1798, p. 407 ; Say, 1817, p. 167; Harlan, 1835, p. 230. f. 3; Gould, 1841, p. 330 ; Thompson, 
1842, p. 170; De Kay, 1844, p. 22, Pl. 8, f. 25; Gibbes, 1850, p. 195, (partim). 
Astacus ciliaris Rafinesque, 1817. p. 42. 
Astacus pusillus Rafinesque, 1817, p. 42. 
Astacus affinis Milne-Edwards, 1437, p. 332 (non Say). 
Cambarus bartoni Girard, 1852, p. 88; Bell, 1859, p. 210; Hagen, 1870, p. 75, Pl. 1, f. 47-50, Pl. 2, f. 135-139, Pl. 3, 
f. 166; Abbott, 1873, p. 80; Smith, 1874, p. 639 ; Putnam, 1874, p. 191 ; Faxon, 1884), p. 22; Faxon, 1885a, p. 
59; Faxon, 1885), p. 358; Underwood, 1886, p. 367; Ganong, 1887, p. 74; Faxon, 1890, p. 622; Hay, 1896, p. 
487, f. 6; Faxon, 1898, p. 649; Osburn and Williamson, 1898, p. 21; Williamson, 1899, p. 47; Hay, 1899, p. 
959, 966 ; Williamson, 1901, p. 11; Ortmann, 1905a, p. 390 ; Paulmier, 1805, p. 134, f. 6 ; Rathbun, 1905, p. 18. 
Cambarus pusillus and montanus Girard, 1852, p. 88. 
Cambarus (Bartonius) bartoni Ortmann, 19050, p. 120, 134. 
Body robust, very sparsely pubescent in fresh, but perfectly naked in old speci- 
mens, with only a few hairs on the fingers of the chelee, and sometimes a slight 
pubescence on the cutting edge of the fingers. 
Carapace subovate, strongly depressed. G:H:B=1:1.3 or 1.4:1.5 or 1.6. 
Greatest width of branchial regions well forward, at a short distance behind the 
cervical groove. Upper surface of carapace very flat. 
Cervical groove deep, not interrupted on the sides. Areola distinctly longer than 
half of the anterior section of carapace; a:p=1:0.6 Areola rather broad (w:/ 
= 1:5 or 6), with about 3-5 irregular rows of punctures. 
Rostrum (Plate XX XTX, Fig. la-1f) broad and short, reaching generally to the 
distal end of the second joint of the peduncle of the antennula, and hardly be- 
yond the middle of the fourth joint of the peduncle of the antenna. Upper surface 
almost flat or only slightly concave, but margins elevated, without marginal spines. 
The margins converge more or less from the base, sometimes they are almost par- 
allel, and near the apex they are suddenly contracted into a short, triangular acu- 
men having a sharp point. ‘The angles at the base of the acumen are rounded, but 
generally well marked, and the elevated margins are continued to the apex, al- 
though slightly decreasing distally from the lateral angles. Postorbital ridges short, 
almost parallel, angulated anteriorly, but without spine, except in young 
specimens. 
Surface of carapace, punctate, distinctly granulated on the hepatic region in larger 
specimens. There are also a few more or less distinct granulations immediately be- 
hind the cervical groove, but no spine. External orbital angle well marked by an 
angulation or a small tubercle, more rarely, and only in young specimens, spiniform. 
Branchiostegal spine formed by a small tubercle, which is sometimes obsolete. 
