236 FOSSIL FL OR A OF ALA SKA— E 1^0 WL TON. vol.. Xvi, 



EXPLANATION OF TlIK TABLE. 



A few words as to the mauner in whicli the table was compiled may 

 be of assistance in understanding its scope. I have given in the tirst 

 ten columns the distribution of the fossil plants in Alaska itself- These 

 columns also show the plants that are confined in their distribution to 

 Alaska so far as now known. The remainder of the table is devoted 

 to those having a distribution outside of Alaska, with the exception of 

 those from Cape Lisburn. As those belong clearly to a much older 

 horizon (]S[eocomian) about which there is little or no doubt, it has 

 been thought unnecessary to increase the size of the table so as to 

 show them.* 



The next eight columns are devoted to the distribution of the Tertiary 

 l^lants of Alaska in the United States and British Columbia. I have 

 then selected a number of typical localities in different parts of the 

 world at which places an abundant uj^per Tertiary flora isdeveloped, such 

 as Disco Island and Atanekerdluk, Greenland, Spitzbergen, Sachaliu, 

 Sinigalia, (Eningen, etc. The last three columns are reserved for Olig- 

 ocene, Miocene, and Pliocene, when the species under discussion is not 

 found in any of the selected typical localities, yet occurs in these hori- 

 zons in other localities. 



DISCUSSION OF THE TABLE. 



The fossil flora of Alaska as presented in this paper embraces 115 

 forms. Of this number 1 is regarded as extra-limital and 3 are inter- 

 glacial, being found also living about the Muir Glacier. Of the 111 

 forms remaining no less than 46 are peculiar to Alaska, leaving 64 

 forms having an outside distribution. On removing the 9 species 

 found at Cape Lisburn about which, as pointed out- above, there is little 

 question of age, we have remaining only 55 species or a little less than 

 50 per cent upon which to depend for the determination of the bearing 

 of the plants on the question of. age. 



An examination of the table yields the following numerical results: 

 The Laramie has 3 species, of which 1 is doubtful; the Post Laramie 

 beds of Colorado 10 species; the Livingston beds of Montana 6 species; 

 the Fort Union beds 16 species, of which 1 is doubtful; the Green River 

 Group 9 species, of which 3 are in doubt; the Mackenzie River 11 

 species; British Columbia has 7 species in the Miocene and 4 in the 

 Laramie, with 2 common to both; California, represented by the aurif- 

 erous gravels and allied formations, has 17 species, of which 3 are in 

 doubt; the Eocene (Alum Bay, etc.) 6 species; the Greenland Miocene, 

 as represented at Bisco Island, Atanekerdluk, etc., has 29 species; 

 the Miocene of Spitzbergen 20 species; the island of Sachaliu (Siberia) 

 23 species; Sinigalia (Italy) 12 species; the so-called Baltic Miocene 



* The Cape Lisburn plants will be treated by Prof. Lester F. Ward iu his forth- 

 coiuing paper on the correlation of the fossil plants of the Lower Cretaceous. 



