Section IV., 1904 [ 57 ] Trans. R. S. C. 



III. — Noies on Tcrlianj Fiants from Canada and Ike United Slates. 



By D. P. Peniiallow. 



(Read June 23, 1904.) 



In continuation of previously recorded studies of undetermined 

 material in the collections of the Peter Kedpath Museum/ the few 

 remaining specimens have since heen determined. For the most part 

 the material was too poorly preserved to admit of precise reference to' 

 any particular species,! although the genera could be ascertainicd with 

 a fair measure of certainty in nearly all cases. A few new facts have 

 been brought to light, however, cihiefly with reference to a revision of 

 previously assigned characters and the relation of extinct forms to exist- 

 ing types. As in the case of previously described specimens from 

 the same horizons, the material was in all cases highly silicified, and in 

 several instances it showed the effects of advanced decay and modifica- 

 tion by compression. 



Taxodium laramianum, n. sp. 

 Laramie formation (Eocene) at Cochrane, Alberta, N.W.T. 



Ti-ffrtsrerse.— Growth rings prominent, rather broad. Summer wood prominent, 

 upwards of 17 tracheids, thick, and passing somewhat gradually into 

 the broad spring wood. Spring tracheids large, squarish-hexagonal, 

 thin-walled, uniform in regular rows. Resin cells obscure, and' 

 forming an open zone on the mner face of the summer wood. Resin 

 passages wholly wanting. Medullary rays numerous, narrow, dis- 

 tant about 2-8 rows of tracheids. 



A'ffrfifl/.— Medullary rays wholly devoid of tracheids. Ray cells straight, equal 

 to about 3 tracheids; the upper and lower walls rather thick and 

 sparingly pitted; the terminal walls straight or diagonal or some- 

 times curved, entire; the lateral walls with oval or round pits, about 

 2-3 per tracheid in radial series. Bordered pits numerous, but be- 

 coming 2-rowed toward the summer wood, though distinctly crowded 

 into 2-3 compact rows in the younger spring tracheids. Resin cells 

 not conspicuous. 



Tangential.— Resin cells conspicuous but not numerous, about three times longer 

 than broad. Medullary rays rather numerous and narrow, often 

 very high, strictly uniseriate; the cells oval, more rarely round in 

 the low rays. 



The specimen to which this diagnosis refers is an undoubted 

 Taxodium. The only fossil representatives! of the genus with which 

 comparison can be made are T. distichum, T. distichum miocenum and 



' Trans. R.S.C., IX., iv.. 33. 



