CAMBARUS. 19 



in the genus Astacus, and in its general form agrees with the corresponding 

 Hnib in tlie other Cambari. Remarks on the rehitions of this interesting 

 species will be found on page 42. 



I am disposed to regard the Cambari of this group as, on the whole, the 

 lowest forms in the genus. The slight degree of specialization of the exter- 

 nal male appendages, the tendency toward an oval, astacoid form of body, 

 the slender claws and generally toothed rostrum, all point to tliis. That 

 the stout-clawed species with toothless rostrum are derived from forms with 

 slender chelae and toothed rostra seems probable from the ftict that the latter 

 characters are commonly found in very young individuals of all species. 



This group corresponds exactly with Group I. of Hagen's Monograph. 



' ,. . ^, 11-1  C Epistomn roiiiidcd in tVont : C. Blundinqii, C. 



Section of tlie carapace bdmulcervi- \ ^ ^j . ^ ,,/^^,,.^ 



eal groove long (see p. lo). i "Fi 



Rostrum toothed, i 



eal groove long (see p. 18). ^ Epistonm truncate : C. Clarh-ii, C. troglodj/tes. 



T, . . ,. . 1 i f Areola narrow : C. Lecontei. 



Posterior section of carapace short > ^j.^,,_,,.^ ^^,^^^ . ^ ,p;,„iij,,^ c. versutus, C. laujus- 



^■^'"^ !'• ^^>- i tatus, C. piibescens. 



Eyes atrophied : C. pelliicidits. 

 Rostrum toothless. G. Wiegmanid, C. penicillatus, C. Alleni. 



1. Cambarus Blandingii. 



Plate VTI. figs. 2, a , S ', 2 a, 3 a (first abdominal appendages of male). 



Astacus Blandinyii, Harlax, Trans. Amcr. Philosopli. Soc, III. 4fii, 1S30. — Medical and Physical Re- 

 searches, p. 229, fig. 1, 1835. 



Astacus Blandinrjii, JIilne Edwards, Histoiiv Naturelle des Crustaces, II. 332, 1837. (After Harlan.) 



Astacus Blandingii, De Kay, Zoology of New York, Part VI. Crustacea, p. 23, 1844. (After Harlan.) 



Astacus {Cambarus) Blandini/ii, Ericiisox, Arch. f. Naturgesch., .Tahrg. XII. , I. 98, 184(5. (After Harlan.) 



^Astacus Blandinrjii, Le Conte, Pmc Acad. Nat. Sci. Phila , VII. 400, 1S53. 



Cambarus Blandingii, Hagex, 111. Cat. Mus. Comp. Zool., No. III., 43, PI. I. figs. 03, 64, PI. III. fig. 140, 

 1870. 



Cambarus acutus, var. B, Hagen, op. cit., p. 30, PI. III. fig. 144, 1870. 



Cambarus acutus, Abbott,'' Ainer. NaturaUst, VII. 80, 1873. (Habits.) 



Cambarus acutus (in part). Smith, Rep. U. S. Comm. Fish and Fisheries for 1872 and 1873, p. 637, 1874. 

 (After Hagcn and Abliolt. No description.) 



Cambarus Blandingii, Faxon, Proc. Amcr. Acad. Arts and Sci., XX. 13.5, 1884. 



Kimvn LocdiiiesA — New York. New Jersey: Essex Co.; Delaware River 

 and tributaries, near Trenton. Maryland : Baltimore Co. (Coll. P. R. Uhler) ; 



* In some specimens of C. /r/////.f the hinder section of the carapace is a little less than one lialf the 

 distance from the cervical groove to the tip of the rostrum. C. maniculatus (LeC.) is omitted from tlie 

 above table, as I have seen no specimens answering to the description of Le Conte. 



t Localities for which no authority is given in parentheses are represented in the collection of tlie 

 Museum of Comparative Zoology. 



