FOSSIL FLORA. 767 



triseriata Caspaiy,' from the Tertiary of Prussia. From this it dififers 

 in the arrangement of ducts and in rays, and somewhat in the markings. 

 It is also evidently allied to the two forms from the Tertiary of Arkansas, 

 LaurinoxijJoii hraiuieri, Kn.^ and L. Icsqiicreuxiaita Kn.^ 



The genus Laurus Avas eAadently abundant in this flora, and it is to be 

 expected that the trunks would be occa.sionally preserved. It is of course 

 pi'obable that this wood may belong to a species that has also been described 

 from the leaves, but there is manifestly no means of connecting them. 



Habitat: Specimen Ridge Forest, near head of Crystal Creek, Yellow- 

 stone National Park, a prostrate log; collected by F. H. Knowlton. August 

 25, 1887. 



Perseoxylon akomaticu:*! Felix. 



Perseorylon aromaficum Felix: Untersuclning iiber fossile Hiilzer, v. Stiick: Zeitsubr. 



d. Deutscli. geol. Gesell., Jahr. 1S96, p. 254, 1800. 

 Laurinojylon aromaticuin Felix : Die Holzopole Uiigarns, p. 27, PI. 1, lig. 7 ; II, fig. 7, 9. 



This species was detected by Felix in his visit to the Yellowstone 

 National Park in 1888. I did not meet with it. 



Habitat: Vicinity of Yanceys, Yellowstone National Park. Collected 

 by J. Felix, 1888. 



Plataninium haydeni Felix. 

 PI. CXX, figs. 3-5. 



Plataninium haydeni Felix: Untersucluing iiber fossile Holzer, v. Stiick: Zeitsclir. d. 

 Deutscli. geol. Gesell. Jalir. 1890, p. 251, 189C. 



Transverse section. — The amuial rings are faint, yet they may be seen with 

 the naked eye. 'I'hey are about 2 mm. broad. The medullary rays are 

 very distinct in the weathered specimen. 



Under the microscope the structure is shown to be well ]>reserved. 

 The wood cells are not arranged 'in radial rows, but are quite irregularly 

 placed. They are large (0.01 to 0.03 mm.) and angular, being 3 to 6 sided 

 by compression. 



' Einige foss. Hc'Hzer Prenssens: Abhaudl. z. geol Specialk. v. Preii.ssen u. Thiiriugi.schen 

 Staateu, 1889, p. 60, PI. XI, flgs. 0-12; PL XII, figs. 1-5. 



-Fossil woods and lignites of Arkansas: Ann. Rept. Geol. Survey Arkansas, 1889, Vol. II, p. 256, 

 PI. IX, figs. 8-9; PI. X, figs. 1,2; Pi. X, fig. 4. 



'Op. cit., p. 258, PI. X, figs. 3,4; PI. XI, figs. 3,4. 



