ORDER DECAPODA—— HOMARUS, 23 
This little Craw-fish, or Fresh-water Lobster, is exceedingly common in most of the 
mountain streams of this and the adjoining States. It has been noticed by Bosc in Carolina, 
and by Dr. Gould in Massachusetts. I am not aware of its extreme northern geographic 
range. Their habits are nocturnal, concealing themselves during the day under stones. They 
are rarely eaten, except by children in sport, although they are undoubtedly as palatable as 
their European congener. The following species I have not seen, although it is said to be 
found in the Delaware. I have searched for it without success in the tributaries of that 
stream within the limits of this State. Milne-Edwards has made a singular transposition of 
the names of these two species. 
(EXTRA-LIMITAL) 
A. affinis. (Sav, loc. cit. p. 168 and 443. Hartav, op. cit. p. 230, pl. fig. 32) Rostrum mucronate, 
subcanaliculate, two-spined; a spine behind each eye, anda larger geminate one on each side of 
the thorax; hand and thumb, on the inner edge, scabrous. Length, 3-3. River Delaware and 
its tributaries. 
A. blandingii. (Harwan, loc. cit. p. 229, pl. fig. 1.) Rostrum mucronate, canaliculate, slightly 
notched at the extremity; aspine behind each eye. Arms tuberculated, elongated; fingers slender, 
unequal ; penultimate and antepenultimate legs of the male with an obtuse process at base of the 
second joint. Length, 38. Marshes and Rivulets of the Southern States. 
A. oreganus. (RANDALL, Jour. Acad. Nat. Sc. Vol. 8, p. 138, pl. 7.) Body granulated; beak a long 
slender spine, with a short spine on each side. Color, fuscous, with a large reddish spot on each 
side posteriorly. Length, 4:0. Oregon Territory. 
GENUS HOMARUS. Edwards. 
Form of the preceding. Rostrum slender, narrow, and armed with many teeth on both sides. 
Eyes spherical. Last ring of the thorax firmly united to the preceding. Hands exces- 
sively developed. Medial caudal plate with lateral spines. Exclusively marine. 
HoMARUS AMERICANUS. 
PLATE XII. FIGS. 52, 53. 
(STATE COLLECTION.) 
Astacus marinus americanus. Sra, Thesaurus, Vol. 3, pl. 17, fig. 3. 
A. marinus. Say, Jour. Acad. Nat. Sciences, Vol. 1, p. 160. 
A, id, Mixne-Epwarps, Hist. Nat. des Crustacés, Vol, 2, p. 334. 
A. id, Goutp, Invertebrata of Massachusetts, p, 330. 
Description. Rostrum narrow, acute, turned up at the tip, with two short spines at its base 
and posterior to the eyes; two or three spines on each side of the rostrum, followed by a 
series of minute ones in large individuals; one or two spines on the under side, near the tip ; 
