E. W. Berry — Potamogeton from Upper Cretaceous. 421 



Potamogeton perry i sp. nov. 



Leaves of relatively large size, elliptical to oblanceolate 

 in general outline; with a roundecl or emarginate apex 

 and an abruptly or gradually narrowed base, decurrent 

 on the broad flat petiole. Leaf substance thin, but firm 

 and not membranous. Length ranging from 7 cm. to 

 10 cm. Maximum width ranging from 1.8 cm. to 2.6 cm. 



Figs. 1-3. — Potamogeton perryi. Natural size. 



Petiole broad and thin, 1.5 cm. in length and about 3 mm. 

 in width, slightly curved, made up of a row of parallel 

 vascular bundles. Midvein similar to the petiole, i. e. 

 broad and flat, not prominent, becoming much attenuated 

 distad by the divergence of vascular bundles. Secon- 

 daries thin, inmiersed in the leaf substance, three or more 

 aerodrome pairs, connected by thin oblique veinlets. 



