404 MEMOIRS OF THE CARNEGIE MUSEUM 



sulcus aljove, and a few more or less distinet tuljercles between sulcus and inner mar- 

 sin. A strong pointed spine in the njiddle 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. 



Merojwdite 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. 



Ischiojwdife of third pereiopods hooked in the male ; hooks in the male of the 

 first form strong, subconical. 



Coxopoditc of fourth pereiopods with a strong, slightly compressed tubercle. 



First plcopods of male (PI. XXXIX, Fig. 11) similar to those of C. bartoni, the 

 tip of the inner psivi, however, tapering gradually to the point. 



Annulus vcntralis of female similar to that of C. curulinns. 



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 foi'm from Nine-^Iile Run, Pitts- 

 burgh, which measures '.)2 \n\n. in length, and a male of tlie second form from Mill- 

 vale, Allegheny County, which is U3 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 ('ounty, Indiana (collected by E. 

 B. Williamson), which is now (in alcohol) 122 mm. long, but measured 124 mm. 

 when alive. 



Color (PI. 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. 



Cround-color on carapace and abdomen from oUvc-green (Ridgway, 1886, X, 18) 

 to raii'-umber (III, 14), mummii-hroion (III, 10) and ferrwjiiieous (IV, 10), shading on 

 the sides through c^m') (III, 18) or russet (III, K^) to fawn-color (III, 22) and whitish. 

 Margins of rostrum rufous (IV, 7) or fer rug ineo us (IV, 10). The hand is taivny-olive 

 (HI, 17) to burnt sienna (IV, 6) and rufou% shading to olive-ijcUow (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 liand crcdni-biiff' {V, 11) or 

 irhifi^h. The legs are ocliruceous-lmff (Y, 10) with nUvr-biiff (W 11), or rnssct (III, 16) 

 with olive-green (X, 18) at the joints. Lower side of body pale rufous or pale 

 orange-huff (VI, 22), or whitish. The antennal flagellum is annulated dark olive- 



