ORTMANN: A MONOGRAPH OF THE NAJADES OF PENNSYLVANIA 347 
. 18. Proptera alata (Say). Ohio River, Industry, Beaver County, Aug. 29, 
1908. Cat. No. 61.3538. Specimen 141. 
19. Paraptera gracilis (Barnes). Ohio River, Industry, Beaver County, July 
11, 1909. Cat. No. 61.4111. Specimen 138. 
. 20. Lampsilis iris (Lea). Conneaut Creek, West Springfield, Erie County, 
May 23, 1909. Cat. No. 61,4091. Specimen 145. 
. 21. Lampsilis recta (Lamarck). Allegheny River, Godfrey, Armstrong 
County, July 23, 1907. Cat. No. 61.2935. Specimen 151. 
. 22. Lampsilis orbiculata (Hildreth). Ohio River, Industry, Beaver County, 
Sept. 23, 1908. Cat. No. 61.3500. Specimen 154. 
. 23. Lampsilis ventricosa (Barnes). Little Beaver Creek, Enon Valley, Law- 
rence County, May 11, 1907. Cat. No. 61.2144. Specimen 169. 
24. Truncilla triquetra Rafinesque. Allegheny River, Kelly, Armstrong 
County, Sept. 27, 1907. Cat. No. 61.2985. Specimen 178. 
