CAMliARUS. 59 



GROUP III. (Tvi-u, C. Bartonii.) 



Third sci/nient of third jiitir of le/j\ hooked. First pair of abdominal appcn- 

 nf Ilif male thick, the inner and outer parts each terminating in a short 

 recurred tooth. 



The moi'e typical forms of this group have no lateral teeth on the ros- 

 trum, but in C. cxtrancus, Jbrdani, Girardianus, cornutus, and hamulatus, lat- 

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

 to Dr. Hagen, Avho placed it on account of the rostral 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. 

 C. cornutus is peculiar in the enormous development of the antennal flagella. 

 C. hamulatus, like C. pcttucidus in Group I., is blind. It has slender chelae, and 

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



(" Areola broad. Rostrum long, tapering ....... C. acuminatus. 



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



Rostrum without I , , 



1 I I ^- reo ' a uarrow ................ C. duLiits. 



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



I Arcola obliterated in the middle. j Rostrum plane above . . C. Uhleri, 



. 1 1 nee rise sedis . . . . C. Neurasccnsis. 



Rostrum with ( Eyes well developed. I Antemuc of llormal sizc ' C ' Giranlianus, C. Jordani, C. ertra^s. 

 ,,,,., 4 [ Antennae with large flagclluin, ciliate ou inner side. C. cornutus. 



I Eyes rudimentary .................. C. hamulatus. 



22. Cambarus Bartonii. 



? Astacus Bartonii, FABRICICS, Suppl. Entomolog. Systcmat., p. 407, 1798. 



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



PI. XL fig. 1, 1830.) 

 ? Astacus Bartonii, LATREILLE, Hist. Nat. Gen. ct Partic. dcs Crustaces et des Insectes, VI. 2-10, 1803. 



(After Fabriciiis.) 



Ax/dcii/t c.Uiaris, RAFINESQUE, Amer. Monthly Mag. and Orit. Rev., II. 42, Nov. 1817. 

 ? Asia, -in piixillns, RAJIXESQUE, Amer. Monthly Mag. and Grit. Rev., II. 42, Nov. 1817 

 Astacus Bartonii, SAT, Jour. Acad. Nat. Sci. Phila., I. 167, Dee. 1.817. 



? Antaeus Bin-loidi-, DESMAREST, Consid. Gen. sur la Classe des Crusfaces, p. 212, 1S25. (After Fabricius.) 

 AX/HI'IIX Biii-tunii, HARLAN, Med. and Phys. Researches, p. 230, fig. 3, 1S35. 

 Astacus nffhiis, MILNE EDWARDS, Hist. Nat. Crust., II. 332, 1837. 

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



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

 Astacus tturtn.iii, DE KAY, Zoology of New York, Part VI., Crustacea, p. 22, PI. VIII. fig. 25, 1844. 

 Cambcn-us Bfir/onii, GIRARD, Proc. Acad. Nat. Sci. Phila., VI. 88, 1852. (No description.) 



