MARYLAND GEOLOGICAL SURVKY 225 



Order FAGALES. 

 Family BETULACEAE. 



Genus CARPINUS Linne. 



Carpinus pseudo-caroliniana n. spt 

 Plate LXXI, Pig. 10. 



Description. — Leaf about 1£ inch long by \ inch wide, oblong; ab- 

 ruptly acuminate at the apex, finely serrate; secondary nerves numerous, 

 fine, sub-parallel, leaving the midrid at an acute angle, and extending to 

 the serrations of the margin. This leaf is almost identical with many 

 smaller leaves of the living C. caroliniana Walt., which are frequently 

 simply instead of doubly serrate. Numerous similar fossil forms have 

 been described under C. grandis ling, and C. heerii Etts., and Lesquereux 

 has figured specimens under the former name from the western United 

 States which approach the Maryland leaves very closely (Tert. PI. pi. 

 lxiv, figs. 8-10). They are described as doubly serrate, although the 

 smaller specimens are figured as simply serrate, the same as the former. 

 Practically the only difference between them is the abruptly acuminate 

 apex of the latter, as compared with the more gradually tapering apex of 

 the former. 



Occurrence. — Sunderland Formation. Near the headwaters of Is- 

 land Creek, Calvert County. 



Collections. — Maryland Geological Survey. 



Genus ALNUS Gaertn. 

 Alnus rugosa (Du Eoi) K. Koch. 



Plate LXIX, Figs. 1-3. 



Betula Alnus rugosa Du Roi, 1771, Harbk. vol. i, p. 112. 

 Alnus rugosa K. Koch, 1872, Dend., vol. ii, pt. 1, p. 635. 



Description. — Numerous leaf impressions of this species occur in the 



fine silt at Drum Point, but it was found almost impossible to preserve 



them long enough for depicting, as they dried and cracked on exposure 



17 



