ORTMANN: monograph of the naiades of PENNSYLVANIA. 143 



remains constant, or varies only within narrow limits, that is the beak-sculpture, 

 which in well-preserved individuals is always double-looped and tubercular. 



Localities in Pennsylvania represented in the Carnegie Museum: 



Ohio-drainage : 

 Smiths Ferry, Beaver Co. (D. A. Atkinson).'' 

 Raccoon Creek, New Sheffield, Beaver Co. 



Ice pond, Edgeworth, Allegheny Co. (G. H. Clapp) (forma gigantea). 

 Beaver River, Wampum, Lawrence Co. (G. H. Clapp & H. H. Smith). '- 

 Brush Creek, Celia, Beaver Co. 

 Glade Run, Zeno, Butler Co. 

 Bonnie Brook, East Butler, Butler Co. 

 Wolf Creek, Grove City, Mercer Co. 

 Mahoning River, Hillsville, LawTence Co. 

 Neshannock Creek, Volant, Lawrence Co. 

 Pymatuning Creek, Pymatuning Township, Mercer Co. 

 Shenango River, SharpsvLlle, Shenango, and Jamestown, Mercer Co.; Linesville, Crawford Co. 



Allegheny-drainage: 

 Pond, Harmarville, Allegheny Co. (forma gigantea). 

 Beaver Run, Delmont, Westmoreland Co. 



Pond, Idlepark, Westmoreland Co. (D. A. Atkinson) (forma gigantea). 

 Crooked Creek, Rosston and Southbend, Armstrong Co.; Creekside, Indiana Co. 

 Cowanshannock Creek, Rural Valley, Armstrong Co. (N. M. Grier). 

 Sandy Creek, Sandy Lake, Mercer Co. 



French Creek, Cochranton, MeadvUle, and Cambridge Springs, Crawford Co. 

 Sugar Creek, Cooperstown, Venango Co. (E. P. Spencer). 

 Conneaut Outlet, Conneautlake, Crawford Co. 

 Conneaut Lake, Crawford Co. (special forms, see above). 

 Cu.ssewago Creek, Mosiertown, Crawford Co. (H. & L. Ellsworth). 

 Conneauttee Creek, Edinboro, Erie Co. 



Conneauttee Lake, Edinboro, Erie Co. (special form, see above). 

 Leboeuf Creek, Waterford, Erie Co. 

 Brokenstraw Creek, Garland, Warren Co. 

 Connewango Creek, RusseU, Warren Co. 



Monongahela-drainage : 

 Monongahela River, Westmoreland Co. (G. A. Ehrmann). 

 Ten Mile Creek, Amity, Washington Co. 

 South Fork Ten Mile Creek, Waynesburg, Greene Co. 

 Dunkard Creek, Wiley and Mount Morris, Greene Co. 



'' Not recorded upon the label whether from the Ohio or from Little Beaver Creek, probably from 

 the latter. 



^- Rhoads (1899) does not give this species from Wampum, and H. 11. Smith also apparently over- 

 looked it, since the specimen, upon which our record is founded, was discovered among duplicates of 

 Strophitus edentulus. 



