PLANTS FROM ALASKA. 1"3 



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

 sents the basal portion of the principal impression enlargefl 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 Xageiopsis longifolia," first found in the 

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

 ditl'erence is not gi'eat. 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 l)y curving sharply. 

 The considerable numl^er of fragments shows that the plant was not 

 uncommon. 



CONCLUSIONS. 



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

 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 sul)ject to doubt. 



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



L Dicksoiiia Sapoitana lleer. One specimen. 



2. Onychiopsis |)silotoides (Stokes & Webb) Ward. Several specimens. 



3. Cladoplilchis vaccensis Ward. One specimen. 



4. Cladophlebis alata Font. Many specimens in proportion. 



.5. ClafTophlebis Huttoni (Dunk.) Font. Proportionally many sj)ecimens. 



6. Podozamites distantinervis Font. Several specimens. 



7. Podozamites grandilolius Font.? Several specimens. 



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



9. Ginkgodium ? alaskense Font. Two specimens. 



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



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



12. Ginkgo Huttoni magnifolia Font.? Several specimens. 



13. Nageiopsis longifolia Font. Proportionally a good many. 



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

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



" Potoiiiac or Younger Mesozoic flora: Monogr. V. S. Geol. Surv., Vol. XV, pp. 19.5, 196, pi. Ix.w, fig. 1; 

 pi. Ix.xvi. figs. 2-6; pi. Ixxvii, fig.s. 1, 2: pi. Ixxviii, figs. 1-.5: pi. Ixxix, fig. 7; pi. xxxv, figs. 1, 2, 8, 9. 



