CAMBAEUS. 121 



Length of chela, 16 mm. Breadth of chela, 7.5 mm. Length of movable 

 finger, 10.5 mm. 



The largest female specimen is 60 millimeters in length. 



Locality. — Cj'press Creek, Lauderdale Co., Ala. 



Nine specimens, four males of the first form and five females, collected 

 bj C. L. Herrick for the U. S. National Museum, October, 1882. 



This is a small species with large hand, slender fingers widely separated 

 at base and meeting only at the tips. In the female there is a heavy beard 

 at base of external finger on the inner side. 



In the summer of 1872, I collected in a Ijrook at Knoxville, Tenn., six 

 specimens, three second-form males and three females, which closely resem- 

 ble those obtained by Mr. Herrick in Alabama, and belong, I think, to the 

 same species. The external finger of the males is densely bearded within at 

 the base, as in the females from Alabama ; the first abdominal appendages 

 reach forward to the base of the second pair of legs, are bifid at the tip, the 

 internal and external parts are thick, blunt at the tip, the outer somewhat 

 longer than the inner, and slightly recurved at the tip. 



GROUP V. (Type, C. Montezumas.) 



Third segment of the second and third pairs of legs hooked. First pair 

 of abdominal appendages of the male similar to those of the species included in 

 Group IV. 



51. Cambarus Montezumse. 



Plate II. fig. 6, Plate X. figs. 7. T, 7 a, 7 a'. 



Cambarus Montezuma, Saussure, Rpv. et ilau'. tie Zool., 2<= Ser., IX. 102, 1S57. — Mem. Soc. Pliys. Hist. 



Nat. Geneve, XIV. 459, PI. III. fig. 22, 1858. 

 Cambarus Montezuma;, var. tridens, VoN Maktens, Arch. Natiirgcscli., XXXVIII. Jabrg., I. 130, 1872. 

 Cambarus Montezuma;, Faxon, Proc. Anici-. Acad. Arts and Sci., XX. 1-19, 1884. 



Cambarus 3Ioutesmnw and C. Shifeldlii are small species distinguished from 

 all the others of the genus by having hooks on the tliird joint of the second 

 and third pairs of legs of the male. In C. Montezumce the rostrum is plane or 

 lightly concave above, with a slightly raised margin ; it varies much in its 

 shape. In the typical form, as described and figured by Sau.ssure, its mar- 

 gins are subparallel from the base to near the extremity, where the}' con- 



16 



