ORTMANN: monograph of the naiades of PENNSYLVANIA. 89 



Neshannock Creek, Eastbrook, Lawrence Co. 



Shenango River, Harbor Bridge and Pulaski, Lawrence Co.; CLarksville, Shenango, and .Jamestown, 



Mercer Co. 

 Pymatuning Creek, Pymatiining Township, iVIercer Co. 



Allegheny-drainage : 

 Allegheny River, Aladdin, Godfrey and Mosgrove, Arm.strong Co.; Walnut Bend, Venango Co.; Tio- 



nesta and Hickory, Forest Co. 

 Buffalo Creek, Harbison, Butler Co. 

 Conemaugh River, New Florence, Westmoreland Co. 

 Loyalhanna River, Idlcpark and Ligonier, Westmoreland Co. 

 Sandy Creek, Sandylake, Mercer Co. 



French Creek, Utica, Venango Co.; Cochranton, Meadville, and Cambridge Springs, Crawford Co. 

 Conneaut Outlet, Conneautlake, Crawford Co. 

 Leboeuf Creek, Waterford, Eric Co. 



Monongahela-drainage: 

 Dunkard Creek, Mount Morris, Greene Co. 

 Cheat River, Cheat Haven, Faj'ette Co. 



Other localities represented in the Carnegie Museum: 



Lake-drainage: 

 Maumee River, Defiance, Defiance Co., Ohio, and Fort Wayne, Allen Co., Indiana (C. Goodrich). 



Ohio-drainage: 

 Tuscarawas River, Ohio (Holland collection). 

 Wabash River, Geneva, Adams Co., Indiana (C. Goodrich). 



West Fork River, Lynch Mines, Harrison Co.; Lightburn and Weston, Lewis Co., West Virginia. 

 Little Kanawha River, Burnsville, Braxton Co., West Virginia. 

 North Fork Hughes River, Cornwallis, Ritcliie Co., West Virginia. 

 Elk River, Sutton and Gassaway, Braxton Co.; Shelton, Clay Co., West Virginia. 



Ten7iessee-drainage : 

 Tennessee River, Tuscumbia, Colbert Co., Alabama (H. H. Smith). 



Distribution and Ecology in Pennsylvania (See fig. 9) : The range of this species 

 in Pennsylvania is very similar to that of P. obliquum coccineum, with the exception 

 that it does not go into the lake-drainage. The two forms are very often found 

 associated. P. clava does not go up the Allegheny as far as coccineum does." 



Altogether, P. clava is a rare shell, and never found in great numbers. It is 

 found mostly in sand and fine gravel, and is deeply buried. In the large rivers it is 

 missing. The lowest point in the Allegheny is at Aladdin. It has never been 

 found in the ^lonongahela proper and in the Ohio, and is also missing in the lists 

 of the older collectors (Stupakoff, Clapp, Rhoads). The same holds good farther 

 down the Ohio. I have never seen a trace of it between Pittsburgh and Cincinnati. 



General distribution: Type locality, "Lake Erie" (Lamarck). 



" I found P. clava as far up as Hickory, Forest Co., but Marshall (1895) reports it from Warren Co. 



