ORTMANN : THE CRAWFISHES OF THE' STATE OF PENNSYLVANIA 451 



northwest a more continuous and solid colony lias remnined. The scarcity or even 

 absence of the typical harloni in Erie County, Pa., which in our state is the chief 

 domain of C. bartoni rohuslus, would support this view. C. harttmi has not yet in- 

 vaded this region to such a degree as to crowd out the other form. Though I must 

 confess that it does not strike me as very likely that the smaller form should be able 

 to conquer the larger one. 



Further investigations on this question should be made outside of this state. 



5. Camhanis carolinus. 

 a. Sumniari/ of Facts. (See pp. 396-397.) 



This species (see PL XLIII) is found in Pennsylvania in the southern part of 

 the Alleghany Plateau, between the Chestnut Ridge in the we.st, and the Alleghany 

 Front in the east, preferring the high valleys in this region. l)Ut not going up to the 

 highest elevations of the mountains. Thus, although abundant near Meyersdale in 

 Somerset County, it does not go up the valley of Flaugherty Creek toward Sand- 

 patch. I have searched for it in vain between Meyei-sdale and Keystone, and at 

 Sandpatch. In a northern direction this species ranges in the valley between the 

 Chestnut Ridge and the Laurel Hill Ridge as far as southern Westmoreland County. 

 Here the northern boundary is formed by the cross-divide in this valley separating 

 the headwaters of Indian ( "reek from the Ligonier \'alley. I am quite positive of 

 this boundary, since I have .searched in vain for chimney-builders all over Ligonier 

 Valley from Idlepark (below Ligonier) to the sources of the Loyalhanna River. 

 Coming across the divide to Jones' Mills, within a short time I discovered this species. 

 In the longitudinal valley between the Launl Hill Kidge and the Alleghany Front, 

 this species has advanced further north. It has crossed the divide between the Cas- 

 tleman River drainage and that of Stony Creek (tributary to the Conemaugh), and 

 I found it near Listie and Windl)er, in Somerset ( 'ounty. At the latter place it seems 

 to attain its northern boundary. At all events I failed to find it near Ix)vctt in Cam- 

 bria County, in the high valley of Laurel Run. which to all appearance allbrds con- 

 genial conditions for its presence being rather swampy in many places. I have also 

 searched for it unsuccessfully in the region of ( "resson, Cambria (!'ounty, and at 

 several places further north. 



The rest of the range of this species is entirely to the south of this state, in 

 Maryland, West Virginia, Virginia, North and South Carolina (disregarding the 

 isolated report from the Indian Territory, in which 1 do not put much faith). No 

 particulars are known about its boundaries, but in tliis rcu'lon also it is restricted to 

 the mountains. 



