<'AMi;.vi;rs. 19 



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

 limb in the other Cambari. Remarks on the relations 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, astacoicl form of body, 

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

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

 slender cheke and toothed rostra seems probable from the fact 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. 



,. e ,, . C Epistoma rounded iu front: C. Blcindiiwii, C. 



Section of the carapace behind ccrvi- ) IT...- / ///,.* 



l i / ~\ o\ "S fJif'/i-i O 1 . /{frt'f.l . ' 



cal groove long (see p. 18). ^ Epistoma truncate : C. Clarkii, C. troglodytes. 



Rostrum toothed. J rf carapace sllort C Areola narrow^ Z^ ^^ ^ 



( tutus, C. pubescens. 



Eyes atrophied : C. pellucidus. 



> * 



Rostrum toothless. C. Wiegmanni, C. penicillatus, C. Alleni. 



1. Cambarus Blandingii. 



Plate VII. figs. 9, 3, 2', 2 a, 2 a (first abdominal appendages of male). 



Astuciis Bluiiilingii, HARLAN, Trans. Ainer. Philosoph. Soc., III. 464, 1830. Medical and Physical Re- 

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



Axfni-ii.1 Bldiiiliiif/ii, MILNE EDWARDS, Histoiro Naturelle des Crustaces, II. 332, 1837. (After Harlan.) 



Antficits Bluiiiliiif/ii, DE KAY, Zoology of New York, Part VI. Crustacea, p. 23, 1844. (After Harlan.) 



Astacus (Cambarus) Blandingii, ERICHSON, Arch. f. Naturgescli., Jalirg. XII., I. 98, 1846. (After Harlau.) 



? Astacus lilinii/inr/ii, LE COSTS, Proc. Acad. Nat. Sci. Phila , VII. 400, 1855. 



Cambarus JUmiilingii, HAGEN, 111. Cat. Mus. Comp. Zool, No. III., 43, PI. I. figs. 63, 64, PL III. fig. 140, 

 1870. 



Cambarus uctitus, var. B, HAGEN, op. cit., p. 36, PI. III. fig. 144, 1870. 



Ciiiiilidi-itx ncn/tis, ABBOTT, Ainer. Naturalist, VII. SO, 1873. (Habits.) 



Cautbants actitus (in part), SMITH, Rep. U. S. Comm. Fish and Fisheries for 1872 and 1873, p. 637, 1874. 

 (After Hagen and Alil><>it. Xo description.) 



Cambarus BlaiuUiigii, FAXOS, Proc. Amer. Acad. Arts and Sei., XX. 135, 1884. 



Known Localities.^ New York. New Jersey: Essex Co.; Delaware River 

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



* In some specimens of C. falhix the hinder section of the carapace is a little less than one half the 

 distance from the cervical groove to the tip of the rostrum. C. iiiiiiiiciilnftts (LrC.) is omitted from the 

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



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

 Museum of Comparative Zoology. 



