404 MEMOIRS OF THE CARNEGIE MUSEUM 
sulcus above, and a few more or less distinct tubercles between sulcus and inner mar- 
gin. A strong pointed spine in the middle of the inner margin, straight, and di- 
rected obliquely forward. A tubercle or spine on anterior margin of lower side, and 
a low tubercle at articulation with hand. A few additional tubercles may be pres- 
ent on the inner margin and the lower side, but they are very rarely spiniform. 
Meropodite smooth, with 1-3 indistinct tubercles near the distal end of the upper 
margin. Lower side with an outer row of 1-4, and an inner row of 7-11 spiniform 
tubercles. 
Ischiopodite of third pereiopods hooked in the male; hooks in the male of the 
first form strong, subconical. 
Coxopodite of fourth pereiopods with a strong, shightly compressed tubercle. 
First pleopods of male (Pl. XX XIX, Fig. 11) similar to those of C. bartoni, the 
tip of the inner part, however, tapering gradually to the point. 
Annulus ventralis of female similar to that of C. carolinus. 
Size. —'The largest specimens at hand from the eastern part of the state are a 
male (first form) and a female from Ridley Park, both 83 mm. long. From the 
western part of the state I have a male of the first form from Nine-Mile Run, Pitts- 
burgh, which measures 92 mm. in length, and a male of the second form from Mill- 
yale, Allegheny County, which is 93 mm. long. The largest female is from Nine- 
Mile Run, and measures 97 mm. in length. 
In the west this species attains a much larger size. The maximum length has 
been recorded by Hagen, 4.5 in. = 115 mm. However, the Carnegie Museum pos- 
sesses a male of the first form from Bluffton, Wells County, Indiana (collected by E. 
B. Williamson), which is now (in alcohol) 122 mm. long, but measured 124 mm. 
when alive. 
Color (Pl. A, Fig. 3). — The color is rather variable within certain limits, but the 
ground-color is similar to that normally seen in crawfishes, brownish or greenish. 
Ground-color on carapace and abdomen from olive-green (Ridgway, 1886, X, 18) 
to raw-umber (III, 14), mummy-brown (III, 10) and ferrugineous (LV, 10), shading on 
the sides through drab (III, 18) or russet (III, 16) to fawn-color (III, 22) and whitish. 
Margins of rostrum rufous (LV, 7) or ferrugineous (LV, 10). The hand is tawny-olive 
(III, 17) to burnt sienna (IV, 6) and rufous, shading to olive-yellow (VI, 16) toward 
the outside. At the bases of the fingers there is often a distinct shade of olive-green 
(X, 21). The finger tips are rufous, the tubercles of the hand cream-buff (V, 11) or 
whitish. ‘The legs are ochraceous-buff (V, 10) with olive-buff (V, 11), or russet (III, 16) 
with olive-green (X, 18) at the joints. Lower side of body pale rufous or pale 
orange-buff (VI, 22), or whitish. The antennal flagellum is annulated dark olive- 
