PLANTS FROM ALASKA. 173 



than any other. It shows also the nerves very distinctly. Fig. 4 repre- 

 sents the basal portion of the principal impression enlarged two diameters. 

 In the mutilated condition of the leaflets and their detached character 

 it is not possible positively to determine the place of this plant. It 

 agrees well with the conifer Nageiopsis longifolia," first found in the 

 Potomac formation. Some of the leaves are rather wider, but the 

 difference is not great. The widest of the Potomac leaves are 12 mm. 

 wide. The leaflets agree especially well with those of figs. 2 and 5 on 

 pi. Ixxvi of the work just cited. The nerves also agree well with those 

 of the Potomac plant. They are sharply defined and rather remote. 

 They are parallel and simple to the base of the leaflets. At the base, 

 on entering the pedicel, they fork once and converge by curving sharply. 

 The considerable number of fragments shows that the plant was not 

 uncommon. 



CONCLUSIONS. 



In the outset it should be stated that the amount of material in these 

 collections is quite small. Much of that obtained is very imperfect. A 

 large portion of it is composed of two or three species, and there is a 

 lack of decisive fossils. Hence it would be understood that any conclu- 

 sions that may be drawn will be subject to doubt. 



The following is the list of plants which have any significance : 



1. Dicksonia Saportana Heer. One specimen. 



2. Onychiopsis psilotoides (Stokes & Webb) Ward. Several specimens. 



3. Cladophlebis vaccensis Ward. One specimen. 



4. Cladophlebis alata Font. Many specimens in proportion. 



5. Cladophlebis Huttoni (Dunk.) Font. Proportionally many specimens. 



6. Podozamites distantinervis Font. Several specimens. 



7. Podozamites grandifolius Font. ? Several specimens. 



8. Baiera gracilis (Bean) Bunb. One specimen. 



9. Ginkgodium ? alaskense Font. Two specimens. 



10. Ginkgo digitata (Brongn.) Heer. Several specimens. 



11. Ginkgo Huttoni (Sternb.) Heer. One specimen. 



12. Ginkgo Huttoni magnifolia Font. ? Several specimens. 

 1.3. Nageiopsis longifolia Font. Proportionally a good many. 



These thirteen forms are by no means equal in value for detennining 

 age. They differ much in the number of specimens and in the definiteness 



« Potomac or Younger Mesozoic flora: Monogr. U. S. Geol. Surv., Vol. XV, pp. 195, 196, pi. Ixxv, fig. 1; 

 pi. Ixxvi, figs. 2-6; pi. Ixxvii, figs. 1, 2; pi. l.xxviii, figs. 1-5; pi. Ixxix, fig. 7; pi. xxxv, figs. 1, 2, 8, 9. 



