458 MEMOIRS OF THE CARNEGIE MUSEUM 



this species is not present in the neighborhood of Du Bois and Falls Creek in Clear- 

 field County, although favorable localities are numerous there. In the valley of 

 Red Bank Creek I have looked for it in vain near Brookville, Jefferson County. 

 Fm-ther west the boundary becomes obscui'e, and is marked by the following locali- 

 ties: Kittanning in Armstrong County ; Renfrew and Branchton in Butler County; 

 and Mercer in Mercer County. At all e\'ents I found this species at the jdaces 

 named, but not north of them. Since no apparent physical feature marks the 

 boundary in these parts, it reiuains doul)tful whether this is the actual noi'thern 

 limit of distribution ; but we can narrow down the zone in which it must l)e situ- 

 ated by naming a few more northern places where 1 searched for it in vain at 

 the proper places: Goodville, Indiana County;''"' Templeton, Armstrong County 

 (swampy places of the Alleghany river-bottoms) ; Oil ( 'ity, Venango County ; 

 the region of the Pymatuning 8wamp near Linesville antl Summit, Crawford 

 County. It seems, however, that toward the west the boundary has the 

 tendency to run in a n<jrthwesterly direction, and in Ohio this species reaches 

 the Lake Erie drainage in Lorain ( 'ounty (Oberlin). 



Within the region above defined this species is generally found at a slightly lower 

 altitude than (J. 'ntononyalcyisis. It is, however, not preeminently characteristic of 

 the river-bottoms, as I formerly believed (1905«, p. 400), but is chiefly distributed 

 at an elevation of about 900 feet (more or less), that is to say, at about the level of 

 the valley of the Old Monongahela River of Preglacial times. At the foot of the 

 Chestnut Ridge it goes up to L200 feet and more, the highest point being Donohoe, 

 Westmoreland (Jounty, 1,260 feet, but on the other hand it descends to the river- 

 bottoms, between 600 and 700 feet, the lowest elevation observed being ou the Ohio 

 river-bottoms at New Martinsville, West Virginia, about 600 feet. Thus C. diogcnes 

 is quite abundant at about 900 feet, where C. monongalensis is decidedly rare ; above 

 this C. diogencs is rai-e, while C. monongalensis has its chief domain at this level ; 

 and below 900 feet C. diogcnes is also abundant, while C. monongalensis is found 

 only in exceptional cases. 



While the boundaries of this species in Pennsylvania are tolerably well known, 

 it is quite different with the rest of the range. It appears that the range is divided 

 into two unequal, discontinuous parts, an eastern and a western. The eastern com- 

 prises, aside from the small section of Pennsylvania along the Delaware River, the 

 whole or poilions of New Jersey, Delaware, Maryland, the District of Columbia, 

 Virginia, and North Carolina. Here it seems to be found exclusively in the Coastal 



"This is in the same valley as at Pnuxsutawney, but C. diogenes is positively not found here, since a splendid 

 place was found for it where it ought to have been discovered if at all present in the neighborhood. 



