Plate XXI. FILICALES: NEUROPTERIDAE 



1. Neuropteris clarksoni Lesquereux, from Mazon Creek, x 1/2, 

 U C Coll. No. 32031. 



2-3. Neuropteris flexuosa Sternberg, from Mazon Creek, x 2/3, U 

 C Coll. No. 32032 and No. 32083. 



4. Neuropteris ovata Hoffman, from Mazon Creek, x 2/3, U I 



Coll. No. P 1289. 



5. Neuropteris crenulata Brongniart, from Mazon Creek, x 2/3, 



U I Coll. No. P 1290. 



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