680 The Smithsonian Institution 



gate, New Mexico, consisting of three specimens of fossilized 

 tree trunks. The specimens were described as a new species, 

 and called Araucarites Arizonicum. 



The second paper, issued in 1888, is founded on coniferous 

 specimens, and describes two species of the genus Cupressi- 

 noxylon. The horizon of one of the species is probably Cre- 

 taceous, the other is Laramie. 



A third paper, published in 1889, embraces descriptions of 

 fifty species of the genus Araucarioxylon of Kraus, with 

 compiled descriptions and partial synonymy of the species. 

 As the evidence which has led to the separation of Cordaites 

 is of interest, Knowlton presents it in full. 



Descriptions of new species of fossil plants from the Fort 

 Union group of Montana appeared in 1893, and a review of 

 the extinct flora of Alaska in 1894. 



The latter paper gives a historical review of works and 

 papers relating to the fossil flora of Alaska, and incident- 

 ally shows the geographical distribution of the plant beds. 

 This is followed by a systematic enumeration of the fossil 

 plants, with descriptions of new species from Herendeen 

 Bay, a table showing the distribution of the plants in other 

 parts of the world ; and, finally, a discussion of the geological 

 age of the beds as indicated, by the plants. 



Other important works during this period were Lester 

 F. Ward's " Paleontologic History of the Genus Platanus," 

 published in 1888, and Holm's " Notes on the Leaves of 

 Liriodendron," issued in 1890. The object of the latter is to 

 prove that there is no greater difference in the foliage between 

 many of the extinct species of Liriodendron than between a 

 series of leaves from a very young tree or from a branch of 

 an older plant of recent species. 



The list of paleobotanical papers published up to date ends 

 with D. P. Penhallow's "Notes on Some Devonian Plants from 



