1852.) 87 
‘The Committee on the following paper by Mr. Charles Girard, of 
Washington, reported in favor of publication in the Proceedings: 
A Revision of the North American Astaci, with observations on their habits and 
geographical distribution. : 
By Caries GIRARD. 
According to recent investigations,* the crawfishes or Astaci, have been dis- 
tributed into several genera: thus, the genus Astacws proper includes all the 
species of Europe and Asia, and two of Australia; the genus Astacotdes is com- 
posed of two species—one from Madagascar and another from Van Diemen’s 
Land; the genus Cheraps comprehends three species peculiar to New Holland ; 
the genus Eng@us embraces two species confined to Van Diemen’s Land; and 
finally, the genus Cambarus includes the American species: one from Chili, 
another from Cuba, two from Mexico and six from the United States. 
Investigations of a still more recent date,f the results of which have not yet 
been given to the scientific world, refer to the genus Astacus a species from the 
Columbia river, thus giving again that genus to North America. 
At the request of Dr.Baird, we have examined critically the Astaci preserved at 
the Smithsonian Institution, collected chiefly by himself. Our’researches have 
made us acquainted with several new species within the limits of the United 
States, and which we now characterise briefly, deferring to another opportunity 
more full descriptions, accompanied with necessary graphic illustrations. 
First growp.—Rostrum subquadrangularly elongated, terminated anteriorly by 
three conical and acute spines, the two lateral smaller than the middle one, 
which forms the tip. Extremity of the anterior pair of abdominal legs (in the 
male) straight and acute. 
1. CamBarus PELLUcIDUS, Erichs. Arch. f. Naturg. 1846, i. 95. 
Astacus pelluctdus, Teun. in Mill. Archiv, 1844, 383. 
Locality.—Mammoth Cave, Kentucky, (Tellkampf, &c.) 
2. CampBarus arrinis, Erichs. Arch. f. Naturg. 1846, i. 96. 
Astacus affints, Say, Journ.Acad. Nat. Sc. Philad. 1. 1817, 168 and 443.— 
Haru. Med. and Phys. Res. 1835, 230, fig. 2. 
A. Bartonti, M. Epvw. Hist. Nat. Crust. ii. 331. 
A. limosus, Ravin. Amer. Month. Mag. ti. 1817, 42. 
Localities.—Schuylkill, at Reading (Baird), Delaware (Say and Rafinesque). 
3. CamBarus orEGaANus, Erichs. Arch. f. Naturg. 1846, i. 375. 
Astacus oreganus, Ranp. Journ. Acad. Nat. Sc. Philad. vill. 1, 1839, 
138, Pl. vir. 
Locality.—Columbia River (Nuttall). 
4. CampBarus Prater, Girard.—Differs from C. afinis in having longer anten- 
nz, and a broader area between the dorsal lines of suture of the carapace. The 
lateral spine of the rostrum are also much less developed. The color is green- 
ish brown above, with small green dots on the claws, and sometimes on the 
cephalo-thorax. »A green line or narrow band is observed along ‘the outer edge 
of the big claws, the tips of which, as well as the tips of the other legs, are 
orange, preceded by a deep green, almost black circle or ring. On each articu- 
lation of the tail there is a double, irregular and transverse blood-red band, 
which extends to the lateral appendages of the caudal rings. Underneath, the 
body is whitish and rusty. 
Locality.—Potomac, at Washington (D. C.) 
* Erichson (W. F.) Uebersicht der Gattung Astacus. — Wiegm. Archiv ftir 
Naturgeschichte, 1846, i. 86. 
{ Proc. Acad. Nat Sc. Philad. vi. 1852, 20. 
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