Section IV., 1903 [ 38 ] Trans. R. S. C 



II. — Notes on Tertiary Plants. 

 By D. P. Penhallow. 



(Read May 19, 1903.) 



Among the undetermined material in the Peter E.edpath Museum 

 of McGill University, my attention has been directed to a collection 

 of fossil woods secured by the late Dr. G. M. Dawson during the pro- 

 gress of the survey under the British North American Boundary Com- 

 mission in 1873-4. The leaf impressions belonging to the collection 

 were studied and reported upon somewhat fully by the late Sir "William 

 Dawson, and they require but little further consideration at this time; 

 the specimens of wood, however, were studied less critically and referred 

 provisionally to several well known genera and specie?.^ \Yhen this 

 material came into my hands, I found that transverse sections had been 

 cut from some of the specimens, while the great majority had not 

 been sectioned at all. With three exceptions, the sections employed 

 by Sir William Dawson for his diagnoses could not be found, while 

 those which were available were found to be unsuited to the purposes 

 of critical study, and they could not be fully identified ^\'ith the hand 

 specimens. It was therefore found desirable to commence de novo 

 and by a careful selection, based upon preliminary sections, it became 

 possible to exclude a large number of the specimens as unfit for further 

 study, and to secure a number in which the structure was well pre- 

 served. The study of these specimens has occupied much time, but 

 the final results as embodied in the following pages, may be regarded 

 as accurately representing our present knowledge of these plants as 

 presented by the stem structure. During the progress of the work it 

 was found possible to identify nearly all the foiins originally described., 

 and to correlate them with recognized species or genera. 



All the specimens were in the form of highly silicified fragments 

 of great hardness. Some of them presented strong external evidence 

 of structure, while others revealed structure only after sectioning. 

 Many of the fragments were angular, showing that they had been 

 found in place, or else that they had been broken from larger speci- 

 mens, while all the smaller specimens, which were in the numerical 

 majoritj', were rounded and well worn through the action of water, 

 indicating that they had been acted upon in place for a long time, 

 or else that they had been transported over a considerable distance, 



' B. N. A. Bound. Comm., 1875. App. 330-331. 



Sec. IV., 1903. 3. 



