no. 1136. OBSEBVATIOXS OX THE A ST AC ID J?— FAXON. 651 



GROUP IV. (Typo, Astacus affinis Say.) 



Third segment of third pair of legs of male hooked. First abdominal 

 appendages of male bifid, terminating in two styliform branches, which 

 are straight or lightly recurved. 



CAMBARUS LANCIFER Hagen. 



Cambarus lancifer Hagen, Monogr. N. A. Astacidfe, p. 59, pi. i, figs. 86, 87; pi. 



in, fig. 159, 1870 (male, Form I). 

 Cambarus faxonii Meek, Amer. Nat., XXVIII, p. 1042, figs. 1-4, 1894 (male, 



Form II). 



In 1891 Mr. W. P. Hay sent me a female specimen of C. lancifer col- 

 lected at Vlcksburg, Mississippi. Up to that time Doctor Hagen's 

 type specimen had remained unique. Mr. Hay's specimen differed from 

 the type in having a median spine on the inner side of the carpus of 

 the chelipeds. In the ''American Naturalist " for December, 1894, Pro- 

 fessor S. E. Meek described and figured the second form of the male 

 under the name of Cambarus faxonii. Professor Meek's specimens were 

 taken in St. Francis Eiver at Greenway and Big Bay, Arkansas. 

 Seven (four males, Form II; three females) have been presented to the 

 Museum of Comparative Zoology (No. 4220). In the second form of 

 the male the tips of the first pair of abdominal appendages are not 

 horny, as in the first form; the inner and outer branches are of about 

 equal length, the inner tapering to a rather sharp, straight point, the 

 outer blunt and rounded. These appendages are cleft only for a short 

 distance from the tip, and so present a form very similar to that seen 

 in Groups I and II. The annulus ventralis of the female is depressed 

 in front, more prominent and unitubercalate behind, with a closed, 

 curved fissure. 



The areola is very incorrectly represented in Meek's fig. 1. The are- 

 ola is entirely obliterated in the middle, not open as there portrayed. 



CAMBARUS INDIANENSIS W. P. Hay. 



Cambarus affinis, var. Faxon, Proc. U. S. Nat. Mus., XXII, 1890, p. 628. 

 Cambarus indianensis Hay, 20th Ann. Rep. Dept. Geol. Indiana, p. 494, fig. 9, 

 1896. 



This form, which I considered as a Western race of Cambarus affinis, 

 has been described as a distinct species by Mr. Hay. It has been found 

 in the Patoka River at Patoka, Indiana, and at Huntington, Dubois 

 County, Indiana. 



CAMBARUS SLOANII Bundy. 



Madison and Marengo, Indiana (fide W. P. Hay). 



CAMBARUS PROPINQUUS Girard. 



Lake Douglas and Saginaw River, Michigan; Indian Lake, Water- 

 loo, Indiana; Portage River at Oak Harbor, Ottawa County, Ohio. 

 (Coll.U.S.N.M.) 



