CA.MI'.ARUS. 27 



differs in some respects from any other seen by me. The granules of the 

 carapace are larger, the gastric area more heavily punctate, the rostrum is 

 longer (14 mm., the whole carapace being 48 mm., while in New Orleans 

 specimens the rostrum is only one fourth the length of the carapace), with 

 longer acumen and lateral spines, and narrower at the base, than in New 

 Orleans specimens, with less converging sides ; the arm is more conspicu- 

 ously tuberculated along its upper edge. The lateral thoracic spines are 

 prominent, as in the San Antonio form. The areola is obliterated in the 

 middle, as in specimens from Louisiana and Alabama. 



A dry cephalothorax.of a female in the Museum of Comparative Zoology 

 (No. 3337), referred to C troylodytes by Hagen (pp. 42, 43), seems to belong 

 to C. Clarkii. As dry specimens are easily transposed, and this is the only 

 specimen recorded from the North, I believe the locality to be erroneous. 



C. Qlurkii is the species commonly on sale in the New Orleans market. 



5. Cambarus troglodytes. 



As/ants troqhclytes, LE CONTE, Proc. Acad. Nat. Sci. Pliila., VII. 400, 1855. 



Astaciis fossar/iHi, LE CONTE, Proc. Acad. Nat Sci. Plula., VII. 401, 1S55. 



Cambants Inylodi/tes, HAGEN, 111. Cat. Mus. Comp. Zool., No. III. p. 41, PI. I. figs. 11-14, PI. II. fig. 141, 



1870. 



Cambarus troglodytes, FOUBES, Bull. 111. Mus. Nat. Hist., No. I. pp. 4, 18, 1876. (After Hageu.) 

 troglodytes, FAXON, Proc. Amer. Acad. Arts and Sci., XX. 136, 1884. 



Knou'ii Localities. Lower Georgia ; Richmond Co., Ga. South Carolina : 

 Charleston; Oakley (Coll. U. S. Nat. Mus.) ; Columbia (Coll. U. S. Nat. Mus.). 

 Illinois: Lawn Ridge, Marshall Co. [?]. 



This species resembles C. Clarkii very closely, but is readily distinguished 

 by the first pair of abdominal legs of the male, and by the rostrum, which 

 is nearly plane above, with very slight marginal teeth (often obsolete), and 

 shorter acumen. The areola is very narrow, but not obliterated, in the 

 middle. 



Two of Le Conte's types (both males, form I.) are extant, one in the 

 Museum of Comparative Zoology, and one in the Academy of Natural 

 Sciences of Philadelphia. In each of these museums there is also a small 

 female type of C. fossarwn of Le Conte, which does not differ essentially 

 from C. troglodytes of the same author. It is difficult to see why Le 

 Conte separated the two, unless on the ground of a difference in color 

 during life. 



