56 A REVISION OF THE ASTACIIU-:. 



obsoletely serrate, as in the male. The superior border of the meros is 

 smooth except at the distal end. The terminal spine of the rib on the 

 inner blade of the swimmerets is inside of the posterior margin. The an- 

 nulus is quite different from that of the other species of this group, viz. 

 C gracilis, advena, and simulans, and I suspect that this female belongs to a 

 species of the C. Bartomi group allied to C. Diogenes and argillicola. 



All the other specimens in the Museum which are referred to C. Caro- 

 linus by Dr. Hagen are small specimens. No. 33G8, dry female from Georgia, 

 L. Agassiz. is certainly 0. advena. No. 3367 (No. 1850 of Hagen), a young 

 female also from Georgia, resembles C. advena in most respects, but the anten- 

 nal scale is too broad near the tip. No. 230, seven young female specimens 

 from Mobile, Ala., and No. 275, a very young male from the same locality, 

 appear to belong to some species of the C. Bartonii group, rather than to the 

 C. advena group, the tips of the male appendages being strongly recurved. 



I am not certain of the identity of Erichson's species. Hagen examined 

 Erichson's type (a male of the first form) in Berlin, in 1870, and thought it 

 was C. Bartonii. Erichson's description, nevertheless, fits the present species 

 very well. The shape of the carapace, the linear areola, the small abdo- 

 men, and the crest-like single row of tubercles on the inner side of the 

 hand, certainly seem to indicate this species rather than 0. Bartomi. Erich- 

 son's type was collected by Dr. Cabanis, who informed Dr. Hagen that all 

 the Astacidae he procured came from near Greenville in the upper part of 

 South Carolina. The specimen in the Museum of Comparative Zoology here 

 referred to C. CaroKnus conies from the seaboard at Charleston. The form 

 of the male appendages of Erichson's type would at once prove or disprove 

 its identity with C. Bartonii. If it be the same, the species under consider- 

 ation must receive a new name, C Hagenianus. The unispinous telson of 

 Erichson's type is probably an abnormal condition, not a specific character. 



21. Cambarus gracilis. 



Plate VIII. llirs. 4, 4, 4" (first abdominal appendages of male). 



Cambarus gracilis, Buhdy, Bull. 111. Mus. Nat. IIi>t . , No. 1. p. 5, L876. — Trans. Wis. Acad. Sci., V. 182, 

 1882. — Gcol. V\ is., Sii.v. of 1S7H-79, I. -103, l^s:;. 



-iii Bull. 111. Mus. Nat. Hist.. No. 1. \> L8, L876. 

 it gracilis, 3?axon, Proe. kmer. A.cad. Arts ami Sci., \\. Ill, 1884. 



.Male, form I. — Rostrum of moderate length, depressed, broad, excavated, 

 foveolate al base ; margins raised, punctate, slightly converging from the 



