10 A REVISION OF THE ASTACIDA. 
flattened hands, belongs alone, then, to Saussure’s C. Azfecus. In the second 
form the antennal scale is more broadly truncate at the end, and the ros- 
trum is a little different. These differences are not striking enough, however, 
to preclude the specific identity of the two forms. 
Of the species of Cambarus described by American authors before the 
date of Hagen’s Monograph, but few types are extant. The oldest known 
to me are Harlan’s, 1830, 1855 (A. Blandingii Har., A. Bartonii Fab., A. affinis 
Say), preserved in the collection of the Academy of Natural Sciences of 
Philadelphia. 
In 1850, Professor Lewis R. Gibbes enumerated, without describing, four 
species of Cambarus under the names Asfacus Barton Fab., A. affiis Say, 
A. Blandingii Harlan, and A. pellucidus Tellk. Several specimens labelled by 
Gibbes in the collection of the Philadelphia Academy and in the Museum 
of Comparative Zodlogy prove that his identifications were often incorrect, 
and consequently the localities given by him cannot be taken as authori- 
tative. Under the name of A. Barto Gibbes appears to have confounded 
three distinct species: C. Burtomi (Fab.), C. datimanus LeC., and C. rusticus 
Gir. (See p. 65.) The localities South Carolina and Alabama cited by 
Gibbes under A. Barlowi probably refer to C. datimanus. Gibbes’s A. affinis 
is the true A. affis of Say, as is shown by a specimen in the Philadelphia 
Academy’s collection ; but the locality, “ Florida,” attributed to this species 
in Gibbes’s paper, undoubtedly belongs to some other species. A specimen 
in the Museum of Comparative Zotlogy, determined as A. Blandingii by 
Gibbes, is C. troglodytes (LeC.); and to this species Gibbes’s habitat, “ the 
low country of South Carolina,” properly appertains 
Girard in his Revision of the North American Astacidse (Proc. Acad. Nat. 
Sci. Phila., 1852) enumerates twenty species of Cambarus, twelve of which 
are new. ‘The diagnoses are in many cases insufficient fer the identification 
of the species, and it therefore becomes highly important to fix the spe- 
cies through an examination of typical specimens. Two of the species in 
Girard’s list, C. fossor (Raf) and C. Oreganus (Randall), were unknown to 
Girard, and remain doubtful to the present day. C. Gambelii (types in the 
Philadelphia Academy) is an Astacus. The types of most of Girard’s species 
were formerly in the collection of the Smithsonian Institution at Washine- 
ton, whence they were transported by Dr. Stimpson to the Chicago Academy 
of Science, and there consumed in the great fire of 1871. Fortunately, 
before their destruction types of five of the eleven new Cambari and two 
