THE CEETACEOUS AND LARAMIE OF CANADA. 33 



Taxites. — Type of Taxus baccata, or of Torreyia, and other yews. Wood with narrow 

 fibres, having discs in one row and numerovis spiral lines. Belly River series, South 

 Saskatchewan (G. M. D.) 



Ginkgo or S.^lisburya. — Type of S. adiantifolin, the Chinese Ginkgo tree. Wood 

 with moderately narrow fibres, having bordered pores in one row, and numerous, very 

 short, medullary rays, having usually only two rows of cells superimposed. The woody 

 fibres sometimes show spiral lines, but much less distinctly than in the previous species. 

 This wood is quite similar to that of the Chinese Ginkgo. South Saskatchewan, Belly 

 Eiver series (G. M. D.) ; west of Medicine Hat (J. W. D.) Similar wood occurs in the 

 Laramie series. 



Thu-ta. — Type of S. occidentalis. Belly River series, Oldman River (G. M. D.) ; Belly 

 River series, Ribstone Creek (J. B.T.) ; Twenty Mile Creek (J. W. D.) 



PiNXJS, or Abies (?) — Type of Pitoxylon of author, with frequent, short, medullary 

 rays, and many resiniferous tubes, and one row of bordered pores, West of Medicine Hat 

 (J. W. D.) 



Exogens. 



The generic names attached to these woods merely indicate a close resemblance to the 

 genera named, in the nature and arrangement of the tissues, so far as ascertained. 



Betula. — Belly River series, Ribstone Creek (J. B. T.) ; Fort Pierre series, head of 

 Swift Current (T. C. W.) 



POPULTJS. — Fort Pierre series, head of Swift Current (T. C. W.) 



Caeya. — Fort Pierre series, head of Swift Current, two specimens (T. C. W.) 



Ulmus. — Fort Pierre group, same locality (T. C. W.) 



Platanus (?)— Belly River series, Ribstone Creek (T. C. W.) 



The above woods are all Upper Cretaceous. With reference to the genus Sequoia, it 

 may be noticed that foliage of a species of this genus, referred to S. Reichenbachii, is exceed- 

 ingly abundant in the shales associated with the coal on the Belly River, and also on the 

 South Saskatchewan. 



With respect to the abundance of exogenous stems relatively to the number of exo- 

 genous leaves found in the Belly River and Fort Pierre series, it is to be observed that, in 

 a marine series like the Fort Pierre, drift trunks are much more likely to occur than leaves. 

 It is also to be observed that leaves of Populas and Platanua occur in the Belly River series 

 near Medicine Hat, and that most of the genera represented by the woods, occur in the 

 Middle or Upper Cretaceous of the Peace River district and of Vancouver Island. 



II. — Lower Laramie Series. 



From this formation there are only five specimens in the collection. Three of these, 

 collected by Mr. Tyrrell and Dr. Dawson at Antler Hill and Edmonton, have the structure 

 of Sequoia, one that of S. gigantea, two that of S. sempervirens. Another specimen shows a 

 taxine structure with short, medvillary rays similar to that of Salisbunja noticed above. 

 The fifth is probably a Tlivja or Arbor vitce. It was collected by Mr. Weston in Scabby 

 Creek. 



Sec. iv, 1887. 5, 



