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. 
Further west the boundary becomes obscure, and is marked by the following loeali- 
ties: Kittanning in Armstrong County; Renfrew and Branchton in Butler County; 
and Mercer in Mercer County. At all events I found this species at the places 
named, but not north of them. Since no apparent physical feature marks the 
boundary in these parts, it remains doubtful whether this is the actual northern 
limit of distribution ; but we can narrow down the zone in which it must be situ- 
ated by naming a few more northern places where I searched for it in vain at 
the proper places: Goodville. Indiana County; Templeton, Armstrong County 
(swampy places of the Alleghany river-bottoms); Oil City, Venango County ; 
the region of the Pymatuning Swamp near Linesville and Summit, Crawford 
County. It seems, however, that toward the west the boundary has the 
tendency to run in a northwesterly direction, and in Ohio this species reaches 
the Lake Erie drainage in Lorain County (Oberlin). 
Within the region above defined this species is generally found at a slightly lower 
altitude than C. monongalensis. It is, however, not preéminently characteristic of 
the river-bottoms, as I formerly believed (1905a, 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 1,200 feet and more, the highest point being Donohoe, 
Westmoreland County, 1,260 feet, but on the other hand it descends to the river- 
bottoms, between 600 and 700 feet, the lowest elevation observed being on the Ohio 
river-bottoms at New Martinsville, West Virginia, about 600 feet. Thus C. diogenes 
is quite abundant at about 900 feet, where C. monongalensis is decidedly rare ; above 
this C. diogenes is rare, while C. monongalensis has its chief domain at this level ; 
and below 900 feet C. diogenes 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 portions of New Jersey, Delaware, Maryland, the District of Columbia, 
Virginia, and North Carolina. Here it seems to be found exclusively in the Coastal 
This isin the same valley as at Punxsutawney, 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. 
