Maryland G-eological Survey 401 



A very large number, perhaps as many as two hundred, fossil species 

 of Pinus have been described, ranging in age from the Jurassic upward. 

 The Jurassic has furnished pine-like leaves, as well as the remains of 

 cones, which have formed the foundation of several species. While these 

 records are for the most part not entirely unequivocal, Fliche and 

 Zeiller ^ in a recent communication are positive of the identity of the 

 cone which they describe from the French Portlandian. From horizons 

 homotaxial with the Potomac Group, a number of forms have been re- 

 corded. These include six species described by Heer from leaves in 

 the Kome beds, three species from the Kootanie, one from the Lakota 

 of the Black Hills, and one from the Trinity of Texas. Strata of 

 Albian age in Europe are remarkable for the number, variety and excel- 

 lent preservation of c6nes of Pinus, about a dozen species being known 

 from England, Belgium, and France. The Upper Cretaceous records 

 are frequent and conclusive, including the evidence of wood wdth 

 structure preserved, and the genus beconies thoroughly cosmopolitan 

 during the Tertiary period. The definite remains of Pinus in the 

 Potomac Group are those of both cones and seeds constituting the fol- 

 lowing single species, the cones of which sometimes crowd the strata 

 of the Patapsco formation. In addition, both the older and the younger 

 Potomac contain leaf remains which have been described by Professor 

 Fontaine as species of Lefiostrohus and LaHcopsis. These are obviously 

 not related to Leptostrohus or the modern Larix, and are included by 

 the present writer in the form-genus Ahietites, since the latter type of 

 cones in the English Wealden material (Pinites) are borne on branches 

 bearing long leaves like those named as above by Professor Fontaine. 



Pinus vernonensis Ward 

 Plate LXVI 



Seed of Pinus ? sp., ? Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 



1889, p. 272, pi. clxx, fig. 4. 

 Pinus vernonensis Ward, 1906, in Fontaine, Mon. U. S. Geol. Survey, vol. 



xlviii, 1905, p. 497, pi. cix, figs. 4-6. 



^Fliche and Zeiller, Bull. Soc. Geol. France (iv), t. iv, 1904, p. 804. 



