56 A REVISION OF THE ASTACID.E. 



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

 smooth except at tlie 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 simiilans, and I suspect that this female belongs to a 

 species of the C. Bartonii 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. 3368, dry female from Georgia, 

 L. Agassiz, is certainly C. 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 tlian to the 

 C. advena group, the tips of the nuile 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 G. 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 C. Bartonii. Erich- 

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

 the Astacida) 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. Carolinus comes from the seaboard at Charleston. The form 

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

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

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

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



21. Cambarus gracilis. 



Plate VIII. figs. 4, 4, 4" (first abdominul appendages of male). 



Cambarm gracilis, Bundy, Bull. HI. Mus. Nat. Hist., No. I. p. 5, 1S76. —Trans. Wis. Acad. Sei., V. 1S2, 



]882. — Gcol. Wis., Surv. of 1873-79, I. 403, 1883. 

 Cambarus rjradlis, Forbes, Bull. 111. Mus. Nat. Hist., No. I. p. 18, 1870. 

 Cumharus gracilis, Faxon, Proc. Amer. Acad. Arts and Sci., XX. 141, 1884. 



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

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



