FOSSIL FLORA. 767 



triseriata Caspaiy, 1 from the Tertiary of Prussia, From this it differs 

 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, 

 Laurinoxylon branneri Kn. 2 and L. lesquereuxiana Kn. 3 



The genus Laurus was evidently abundant in this flora, and it is to be 

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

 probable 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 akomaticum Felix. 



Perseoxylon aromaticum Felix: Untersuchung fiber fossile Holzer, v. Stuck: Zeitschr. 



d. Deutsch. geol. Gesell., Jahr. 1896, p. 254, 1890. 

 Laurinoxylon aromaticum Felix : Die Holzopole Uiigarns, p. 27, PI. I, fig. 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. OXX, figs. 3-5. 



Plataninium haydeni Felix: Untersucbung fiber fossile Holzer, v. Stuck: Zeitschr. d. 

 Deutscb. geol. Gesell. Jabr. 1896, p. 251, 1896. 



Transverse section. — The annual ring's are faint, yet they may be seen with 

 the naked eye. They 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 preserved. 

 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. Holzer Prenssens: Abkandl. z. geol Specialk. v. Prenssen n. Thiiringischen 

 Staaten, 1889, p. 60, PI. XI, figs. 6-12; PI. XII, figs. 1-5. 



2 Fossil woods and lignites of Arkausas: Ann. Rent. Geol. Survey Arkansas, 1889, Vol. 11, p. 256, 

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



'6p. eit., p. 258, PI. X, figs. 3,4; PI. XI, figs. 3,4. 



