Plate XXXVI. FILICALES: PECOPTERIDAE 



1-4. Ptychocarpus unita (Brongniart) Weiss, with sori. 



Nos. 1, 3, and 4. From Mazon Creek, U C Coll. No. 32049-51. 



No. 2. From Mazon Creek, x 2/l, U C Coll. No. 32087. 



90 



