4 A REVISION OF THE ASTACHXE. 



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

 C. Montezumce and 0. ShafelcUii the second and third), or the third and fourth 

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

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

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

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

 mate thoracic somite ; t and in this sex the first pair of abdominal appen- 

 dages, though 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 widely 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, t but little has been added to our knowledge of these 

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

 year 1868 has been given with sufficient fulness on pages 5-12 of Hagen'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. ami Mag. of Nat. Hist, 4tli Ser., 

 Vol. VIII. pp. 368-370), records the capture of a blind crayfish in the Wyandotte Cave, 

 Crawford Co., Ind. It is considered to he the same as the Mammoth Cave species, 



C. [)' III" i</ US. 



1S7l'. In a "Eeport on the Wyandotte Cave ami its Fauna" (Third and Fourth 

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

 yives a fuller account, accompanied by a figure, of the Wyandotte Cave species, which, 

 after comparison with ('. pellucidus, he concludes to be a new species. This he names 

 Orconectes inn-mis, establishing a new genus for the reception of the two blind species. 



* A detailed description of these appendages will be found on page 17 of Bagen's Monograph ol the 

 N 'i th \i,m rican Antacids. 



t Sec Hagen, up. cil., p. V.). 



% Monograph of the North American Astacidse, bj Dr. Hermann A. Hagen. 111. Cat. Mas Comp 

 Zoo! , No III (Mi in , Vol. II. No. 1), 1870. This monograph was finished in 1SGS, although not published 

 nil two years lit r 



