22 NEW-YORK FAUNA — CRUSTACEA. 
Genus Catxranassa, Leach. Abdomen elongated, membranous. Terminal filaments of the internal 
antenne much longer than the peduncle. No respiratory appendices under the abdomen. 
Lateral plates of the caudal fin foliaceous and very broad. First and second pair of feet di- 
dactyle; third pair enlarged towards their extremities. 
C. major. (Savy, Journ. Ac. Nat. Sc. Vol. 1, p. 238.) Hands unequal: carpus granulated, trilateral, 
not concave. Hand much elongated, sublinear, compressed, glabrous. Abdomen membranaceous, 
of six segments; lateral lamelle- simple, larger than the tail. Length, 4-5. Burrows in sand. 
Florida. 
Genus Grsra, Leach. Characters of the preceding, but the first and second pair of feet with a movable 
finger, and projecting angle for a thumb. Rostrum elongated and broad, concealing the eyes. 
G. affinis. (Say, loc. cit. Vol. 1, p. 241.) Thorax glabrous, covered in front with tufts of hair arising 
from tubercles. Rostrum short, canaliculate, hairy. Hands not broader than the carpus, linear, 
nearly equal to the third joint. Length, 2°25. Coast of Georgia. 
GENUS ASTACUS. Fabricius. 
Rostrum depressed, wide at base, and with not more than one lateral spine. Lamellar 
appendix of the external antenne large; the fifth thoracic ringis articulated with the 
preceding, and not soldered to them. Six anterior feet didactyle. Exclusively fluviatile. 
ASTACUS BARTONIL. 
PLATE VIII. FIG. 25. 
(STATE COLLECTION.) 
Astacus bartonii, Fas. Entom. Systematica, Suppl. p. 407. 
A, id. Bosc, Hist. Nat. des Crust. Vol. 2, p. 62, pl. 11, fig. 1. 
Ae id. Say, Jour. Acad. Nat. Sc. Vol. 1, p. 167. 
A. id. Haran, Med, and Phys. Researches, p. 230, pl. fig. 2. GouLp, loc, cit. p. 330. 
A, affinis. MiLNE-Epwarps, Hist. Nat. des Crustacés, Vol. 2, p. 332. 
Description. Body with scattered punctures. Rostrum mucronate, concave, elongated, 
suddenly attenuated, but with lateral angles rather than spines at the point of attenuation. 
No spines on the thorax. An acute triangular spine, rather exceeding the rostrum in length, 
articulated to the outer side of the base of the external antenne ; below the base of the spine, 
on each side, an oculiform tubercle. Movable finger slightly shorter than its opposite, and 
a number of foveole or pits in such a regular series on both as to produce the appearance of 
one or more elevated lines. Carpus with a deep furrow on its upper surface, and one or 
more spines on its inner angle. Shield with a transversal lunate furrow. The first segment 
of the middle caudal lamella with one or two short spines on each side. 
Color of the body and claws, greenish brown; tips of the rostrum, of the hands and feet 
(and sexual appendices of the male), reddish. Lighter beneath. 
Total length, 2°0-3°0. 
