FOSSIL FLOKA. 769 



Tlie fact that Platanus leaves are very almiulant in the beds surround- 

 iny- the fossil trunks makes it extrenieh" prnl:)al)le that the generic reference 

 is correct. It is of course also jjrobable that some of the leaves belong to 

 the wood here described as different, but as they have never been found 

 attached, it is manifestly unsafe to assume that there was ever organic 

 union. 



A number of fossil species have been described from various jjarts of 

 the world; n()ne, liowever, from North America. The general agreement 

 between these and the one under consideration is close, l)ut the specific 

 differences are marked in certain cases. One of the nearest forms is 

 Platamis klehsii Gasp.,' from the Tertiary of Prussia. It differs in im|)ortant 

 minor characters, as does P. horealis Gasp.,' from the same place. The two 

 species described by Felix, Plataniniuni porosam Felix and I', regidare 

 Felix, have only general resemblance. 



In the original ]M8., which was submitted in March, 189G, I had of 

 course given this another specific name, and it may still prove to be difi'erent 

 from the P. Jiaijdeni of Felix. Unfortunateh* Felix has not figured his 

 species, and it is difficult, from a mere technical description, to be entirely 

 certain of their identit}'. It is reasonably certain, however, that they are 

 identical, and I have so regarded tliem. 



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

 stone National Park. From a trunk 6 inches in diameter and about 1 foot 

 in height; collected by F. H. Knowlton, August 25, 1887. 



Rhamnacinium radiatum Felix. 

 PI. CXVIII, ti-s. G, 7; ri. CXIX, tig. 1. 



RlKtiiniaeiiiiiimnnliittKiii Felix: UntersiicbaiigiiberfossileHolzer: Zeitsi-lii-. d. Deutsch. 

 geol. (iesell., Jabr. 1896, p. 2.5li, PI. VI, tig. 3, 1896. 



Transverse section. — Aunual Hiig broad (7 mm.), verv indi.stinct, consistino- 

 of only 1 or 2 rows of slightly thickened wood cells and rather alirupt 

 presence of numerous large ducts in succeeding spring wood. Ducts very 

 numerous, in radial rows. A few of the ducts are single, but mainly they 

 are contiguous, with 2 to 10 in a series. The usual number is 3 or 



'Eiuige foss. Holzer Preusseus : AbhancU. z. geol. Speeialk. v. Preussen ii. Tliiiringischeu 

 Staateu, 1889, PI. VIII, tigs. 1-24. 

 ■Op. cit.,Pl. IX, figs. 1-11. 

 MON XXXII, PT II 49 



