VII. THK (;RA\V1-'1SHKS ok western PENNSYLVANIA. 

 I!v Dr. a. E. Ortmann. 



Up to the present time, the crawfish fauna of western Pennsylvania 

 was very incompletely known. Aside from the scanty records given 

 in the monographic works on American crawfishes by Ilagen (111. Catal. 

 Mus. Harvard, 3, 1870) and P'axon (Mem. Mus. Harvard, 10, 1885), 

 to which I'a.xon added a few other records (Proc. U. S. Mus., 20, 

 1898), we possess only a list of the species of crawfishes of Allegheny 

 county, published by E. B. Williamson (Ann. Carnegie Mus., i, 

 1901, 8-13). Unfortunately, this list was founded ujjon entirely in- 

 sufficient material, and, consetpiently, later investigations have neces- 

 sitated a number of changes and additions. 



Hagen, in 1870, mentions two species from the State of Pennsyl- 

 vania, of which one {Cambariis affinis) is said to be found also in the 

 western part, at Pittsburgh (pp. 61 and 100, 1. c. ). This record, how- 

 ever, has not been substantiated by subsequent investigations ; CcJi/i- 

 barus affinis being restricted to the eastern portion of the state. 

 Faxon, in 1885 (1. c, p. 165), mentions four species from the 

 state, of which tlirce are also recorded from the western part : Cam- 

 baras barfoui, Canibarus diogenes, and Cambarus riisticus. The 

 latter species is said to come from Pittsburgh ({). no), but, as the 

 writer has ascertained now, this species is not found at Pittsburgh, and 

 has not been found in any other part of the state, although it has 

 been carefully searched for. Thus, the number of species actually 

 known up to that date (1885) is only hvo, namely: Canibarus bar- 

 to ni a.nd Cambarus diogenes. In 1898 (1. c, p. 625) Faxon added a 

 /////v/ species : Canibarus obscurus, from Westmoreland county. 



Williamson, in 1901 (1. c), gave the following yf?^(^ species from 

 Allegheny county : Canibarus bartoni (and var. robusfus), Canibarus 

 diogencs, Canibarus t/iibius, Canibarus propinquus, Cambarus rusti- 

 cus. Closer examination of the material preserved in the Carnegie 

 Museum, that served as a basis for Williamson's paper, and its com- 

 parison with additional material, reveals the fact that only two of these 

 species were correctly identified (^Cambarus bartoni awA Canibaius di- 

 oge?ies), while C dubius turns out to be a new species, and C. propin- 



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