4 A KE VISION OF THE ASTACIDyE. 



short conical tubercle of the basal segment of the antennule. The third (in 

 C. Montezuma' and C Shiifcldiii the second and third), or the third and foiu-th 

 pairs of legs in the male, have a prominent tubercle or liook on the anterior 

 border of the third segment. The first pair of abdominal appendages in tlie 

 male are terminated by styles, hooks, or teeth.* A more or less mobile 

 annulus is situated on the sternum of the female, just behmd the penulti- 

 mate thoracic somite:! and in this sex the first pair of abdominal appen- 

 dages, thougli much smaller than the succeeding pairs, and simple, are 

 somewhat larger than in the genus Astacus. The telson is clearly divided 

 by a transverse suture. 



The genus Cambarus is vpidely distributed over the North American con- 

 tinent, from Lake Winnipeg to Guatemala, from New Brunswick to Wyoming 

 Territory. For a fuller account of the geographical distribution of the genus, 

 the reader is referred to page 178. 



Bibliography of the Genus Cambarus, from the Year 1868 to the 



Present Time. 



Although seventeen years have elapsed since the genus Cambarus was 

 revised by Dr. Hagen, % but little has been added to our knowledge of thes-e 

 animals during that period. The bibliography of tlie genus down to the 

 year 1868 has been given with sufficient fulness on pages 5-12 of Ilagen's 

 memoir. I will briefly mention the works published since that date which 

 treat of these animals. 



1871. E. D. Cope, in an article entitled " Life in the Wyandotte Cave," in the 

 Indianapolis Journal, Sept. 5 (reprinted in Ann. and Mag. of Nat. Hist.; 4th Ser., 

 Vol. VIII. pp. 3G8-370), records the capture of a blind crayfish in the Wyandotte Cave, 

 Crawford Co., Ind. It is considered to be the same as the Mamniotli Cave species, 

 C. pdliccidus. 



1872. In a " Iteport on the Wyandotte Cave and its Fauna" (Third and Fourth 

 Ann. Rep. Geolog. Surv. Ind., pp. 157-182 ; Amer. Nat., Vol. VI. pp. 406-422), Cope 

 gives a fuller account, accompanied by a tigurc, of the Wyandotte Cave species, which, 

 after comparison with C. 2)clhicidus, he concludes to be a new species. This he names 

 Orconcctcs incrmis, establishing a new genus for the reception of the two blind species. 



* A detailed descvi])tioii of t.liese appendages will bo found on page 17 <'f Ilageii's Mnnograiili ol tlie 

 Korih Amoi-icaii Aslacida;. 



t See Hagen, op. rU., p. 19. 



% Monograpli of the Nortli Anicrican Astaeidie, by Dr. Ilennanii A. Hagen. Til. Cat. Mus Comp. 

 Znol, No. III. (Mem., Vol. II. No. 1), 1870. This monograph was fiiushod in ISGS, altliough not published 

 till two years later. 



