OKTMANN: THE CRAWFISHES OF THE STATE OF PENXSYl.VANIA 355 



Annulus ventralis of female transversely rhombiform, with a short transverse 

 groove slightly posterior to the iiiidclle, and an S-shaped longitudinal fissure. An- 

 terior to tlie central groove there is on each side of the fissure a strong, tuberculi- 

 forni elevation, so that the fissure is situated in a rather deep depression. Posterior 

 to the central groove;, theiHs is a slight elevation, over which the fissure passes. The 

 annulus, consequently, appears trituberculate, the two anterior tubercles being 

 stronger than the posterior. In young females, the tubercles are only slightl}' de- 

 veloped, and generally the posterior tubercle is almost obsolete. 



Size. — Rafinesque gives as total length 3-9 inches. The maximum, U in., = 229 

 mm., seems ratlier strange, since no such specimens have ever been subsequently 

 seen, even if we infer that Rafinesque intended the whole length, including 

 the claws. Hagen (1870, pi. 5) figures a very large female, which, including the 

 outstretched claws, would not be longer than about 7 inches (178 mm.). Its body 

 from the tip of the rostrum to the end of the telson, is 132 mm. long. The maxi- 

 mum length given by Hagen in the text (p. 61) is 4.7 in., = 119 mm; thus this 

 figure, altliough said to be of natural size, is apparently somewhat enlarged. 



The largest specimens ever seen by the writer are in the museum of (Jberlin 

 College from the Potomac River, a female measuring 120 mm., and a male of the 

 first form measuring 105 mm. The largest specimen from Pennsylvania I possess, 

 is a female fron) the Delaware River at Torresdale, and measures 93 mm. in length; 

 the largest male (first form) is from the Delaware at Penns Manor, measuring 75 

 mm. in length. A male of the second form from Holmesburs; is 85 mm. lonsr. 

 Specimens over 100 mm. long, mentioned by the writer, (1899, p. 1210), as from 

 Philadelphia, are from the New Jersey side of the river, near Camden. 



Colors. — (Plate B, Fig. 3. ) An account of the color of this species has been given 

 by Faxon (1885a, p. 88). It runs thus: " Upper surface greenish, mottled with 

 darker green, especially on the chelae ; tips of fingei-s orange, preceded by a dark 

 green ring, which runs along the outer border of the hand to the wrists; abdominal 

 somites ornamented with interrupted transverse chestnut-colored double bands. 

 Under surface of a lighter hue." 



1 have repeatedly made notes from live specimens, and have found that the 

 shades of color vary greatly, although the general pattern has l)een correctly 

 described l)y Faxon. The general color of the body may be described as olirc-<jrcen 

 (Ridgway, 1^8(;, X, 18)", but it varies toward tuini;/-olire (III, 17), and olirc-i/cllow 

 (VI, 16). The sides of the carapace are generally lighter, of a whitish green. 



'In the description of colors, I have used licrc (and in tlie following species) the nomenclature of IJidnway (1886), 

 and the Roman and Arabic numerals refer to his plates and figures. 



