404 Systematic Paleontology 



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 Fontaine has in- 

 cluded 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 segregated 

 into four species all of which were 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 variation and due to different stages of macera- 

 tion before preservation, 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 

 formations. 



Similar forms from the English Wealden are described by Carruthers, 

 Gardner, and Seward and referred to the comprehensive genus Pinites of 

 Endlicher (1847). They are in all probability congeneric if not specifi- 

 cally identical with Ahietites macrocarpus Fontaine, whose generic and 

 specific name is here retained since the writer wishes to avoid all unneces- 

 sary changes and Endlicher^s Pinites is antedated anyway by the Pinites 

 of Witham, 1833. In the French Neocomian also, cones of this char- 

 acter are abundant, Cornuel (Bull. Soc. Geol. Fr. (ii), t. xxiii, 1866, 

 pp. 658-673, pi. xii) describing five species from beds of this age and 

 referring them to Pinus. His Pinus suhmarginata is especially sug- 

 gestive of Ahietites macrocarpus Fontaine, as are also some of the species 

 of Pinus described by Coemans ^ from the Lower Cretaceous of Belgium 

 and by Carruthers,^ from the Gault of England. Finally the foliage 

 from the Potomac beds which has been referred to Leptostrohus and 

 Laricopsis is neither Leptostrohus nor related to Larix, and since such 



^ Coemans, E., Mem. Acad. Roy. Belg., tome xxxvi, 1867. 



2 Carruthers, W., Geol. Mag., vol. iil, 1866, pp. 534-546, pi. xx, xxl. 



