CAMBAKUS. 69 



GROUP III. (Type, C. Bartonii.) 



Third segment of third jxdr of legs hacked. First prttV of ahdominal appen- 

 dages of the male thick, the inner and outer parts each terminating in a shoH 

 recurved tooth. 



The more typical forms of this group have no lateral teeth on the ros- 

 trum, but in C extr uncus, Jordaid, Girardianus, cornutus, and hamulatus, lat- 

 eral rostral teeth are present. Of these five, only C. extraneus was known 

 to Dr. Hagen, who placed it, on account of the i-ostral teeth, as an aber- 

 rant species in the C. affinis group. I think the structure of the male ap- 

 pendages is of much greater value in determining the subordinate groups 

 of Cambarus than the form of the rostrum, which presents every condition 

 between one with well-developed lateral teeth and one with entire margins. 

 G. conmtus is peculiar in the enormous development of the antennal flagella. 

 C. hamidaius, like C. 2)cllucidus in Group I., is blind. It has slender chelce, and 

 resembles C. jicllucidus a good deal in its general form. 



Rostrum without 

 lateral teeth. 



' Areola broad. Rostrum long, tapering C. acumhiatus. 



Areola of moderate width C. Bartonii, C. latimanus. 



Areola narrow C. dubius. 



(Rostrum excavated above . C. Diogenes, C.argillicola. 



Rostrum plane above . . C. Vlileri. 



luecrta; scdis .... 6'. Nebrascensis. 



{Ti II J 1 J [ Antenna; of normal size. C. Girardianus, C. Jordani, C. exfraiieus. 

 Eyes well developed. | ^^^^^^^^ ^.^^ ^^^^^ ^^^^^^^^^ ^^^^ ^^ .^^^^ ^^^ ^ ^^^^^^^^^^_ 

 Eyes rudimentary C. hamulatus. 



22. Cambarus Bartonii. 



? Astacus Bartonii, rABMCrcs, Ruppl. Entomolog. Systemat., p. 407, 1798. 



? Astacus Bartonii, Bosc, Histoire Naturelle des Crustaees, II. 62, PI. XI. fig. 1, 1802. (2d cd., II. 40, 



PI. XI. fig. 1, 1830.) 

 ? Astacus Bartonii, L.ytreille, Hist. Nat. Gen. ct Partic. des Crustaees ct des Inscetes, VI. 240, 1803. 



(After Eabrifius.) 

 Astacus ciliaris, Rafinesque, Anier. Montlily Mag. and Crit. Rev., II. 42, Nov. 1817. 

 ? Astacus pusiUus, Rafinesqce, Amcr. Monthly Mag. and Crit. Rev., II. 42, Nov. 1817 

 Astacus Bartonii, Say, Jour. Acad. Nat. Sei. Pliila., I. 167, Dec. 1S17. 



? Astacus Bartonii, Desmaeest, Consid. Gen. sur la Classe des Crustaees, p. 212, 1825. (After Eabricius.) 

 Astacus Bartonii, Harlan, Med. and Phvs. Researches, p. 230, fig. 3, 1835. 

 Astacus affinis, Milne EnwAiuis, Hist. Nat. Crast., II. 332, 1837. 

 Astacus Bartonii, Gould, Rep. Invert. Mass., p. 330, 1841. 



Astacus Bartonii, TnoMr.soN, Hist. Vermont, Part I. p. 170, 1842. (With a worthless cut.) 

 Astacus Bartonii, De Kay, Zoology of New York, Part VI., Crustacea, p. 22, PI. VIII. fig. 25, 1844. 

 Cambarus Bartonii, Gikakd, Proc Acad. Nat. Sci. Phila., VI. 88, 1852. (No description.) 



