312 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



iana in North America is properly identified and distinct from 

 Sequoia ambigua, which is more open and stouter and which may be 

 present in the English Wealden in some at least of the coniferous 

 twigs identified as Sphenolepis stembergiana. 



Occurrence. — Patuxent formation: Fredericksburg, Dutch Gap, 

 Cockpit Point, Potomac Run, Telegraph Station, Virginia; Arundel 

 formation : Soper Hall, Riverdale, Arlington, Muirkirk, Schoolhouse 

 Hill (Hanover), Maryland; Patapsco formation: Federal Hill 

 (Baltimore), Locust (Poplar) Point, Fort Foote, Maryland. 



Collections. — U. S. National Museum, Johns Hopkins University. 



THE GENUS ABIETITES. 



Since its establishment by Hisinger 1 in 1837 this genus has been 

 a convenient and perhaps useful repository for fossils whose real or 

 fancied affinities were thought to suggest the modern genus Abies. 

 They have ranged in age from the Keuper to the Pliocene, the bulk 

 coming from the Cretaceous, and consisting of obscure impressions 

 of foliage and cones, none of which have any real biological value or 

 present any definite clue to their true relationship. Professor Fon- 

 taine has included in this genus fossils from the Triassic of North 

 Carolina and various indefinite remains from the Trinity group of 

 Texas, the Shasta group of California, the Lakota formation of the 

 Black Hills, and the Potomac group of Maryland and Virginia. The 

 latter he segregates into four species, all of which are based upon 

 obscure cone impressions and none of which possess much specific 

 value. When it is remembered what diverse appearances may be 

 assumed by a single species of cone irrespective of individual varia- 

 tion and due merely to different stages of maceration before preserva- 

 tion, to differences in the matrix, and to differences in the direction 

 and force of compression, it seems very probable that we are dealing 

 with a single species of cone, or at least not more than two, instead of 

 the four which are in the literature relating to the Potomac. 



Similar forms from the English Wealden are described by Car- 

 ruthers, Gardner, and Seward, and referred to the comprehensive 

 genus Pinites of Endlicher (1847). They are in all probability con- 

 generic if not specifically identical with Abietites macrocarpus Fon- 

 taine, whose generic and specific name is here retained in order to 

 avoid unnecessary changes and because Endlicher's Pinites is ante- 

 dated by Pinites Witham (1833), something altogether different. In 

 the French Neocomian also, cones of this character are abundant, 

 Cornuel 2 describing five species and referring them to Pinus. His 

 Pinus submarginata is especially suggestive of Abietites macrocarpus 



• Hisinger, Lethsea suecica, 1837, p. 110. 



2 Cornuel, Bull. soc. geol. France (n), vol. 23, 1S66, pp. 658-<373, pi. \2. 



