32 SIE J. W. DAWSON ON FOSSIL WOODS PP.OM 



In describing them I shall follow the order of geological age, and shall refer the 

 specimens to their probable genera without giving them any specific names, as it seems in 

 every way likely that most of them belong to species otherwise named from specimens of 

 their leaves and fruit. I shall append to this paper a few notes on recent discoveries of 

 Laramie ];)lauts, some of which are closely connected with those described in the body of 

 the paper. It may be added, that I have found the classification and nomenclature of the 

 coniferous woods proposed by Goeppert, Kraus, Schroeter and others very imperfect and 

 misleading ; and I agree with Kraus and Schimper, in holding that no specific, or even 

 generic distinctions can be made with absolute certainty, on the evidence of structvire alone. 

 In these circumstances, I have thought it best to compare the structures of the fossil woods 

 with those modern forms which they appeared most to resemble, and especially with those 

 represented by the leaves and fruits found in the same beds. In this way, at least, certain 

 facts will be indicated which may ultimately enable the trunks, known by their structure, 

 to be associated with the other parts of the same trees. As presented in this paper, hoM'- 

 ever, the attainment of this desirable result must be regarded as tentative merely and 

 necessarily imperfect. The exogenous woods examined have been treated in a similar 

 manner ; but as these are often even less perfectly preserved than the conifers, the results 

 are liable to the same uncertainties. 



I. — Belly River and Fort Pierre Series. 



The Belly Eiver beds, which contain many fossil plants and important beds of coal, 

 are believed, on stratigraphical grounds, to underlie the Fort Pierre series, which is marine. 

 (See note in my paper in these Transactions, Yol. IV, 1886). The flora of the Belly 

 River series is, however, very similar to that of the Lower Laramie above the Fort Pierre 

 series, and the trunks of drift trees found in the latter, and referred to below, seem to some 

 extent to connect the two. The greater number of the woods in these formations are 

 coniferous ; but there are some exogeus, most of which are from drift trunks in the Fort 

 Pierre group, while many of the conifers are from beds near to the coal deposits of the 

 Belly River district. 



All these woods, whether coniferous, or augiospermous, have distinct annual layers of 

 growth. 



Conifers. 



Sequoia. — Type of S. gigantea, the " big tree " of California. Wood with wide 

 woody fibres, having large bordered pores in one row, and narrow, simple medullary 

 rays of many rows of cells superimposed. Resin tubes large, but not numerous. 

 Pierre group. Bow River (Gr. M. Dawson) ; Belly River series, Ribstone Creek (J. B. 

 Tyrrell) ; Belly River series, white rocks iihove coal bank (T. C. Weston) ; Belly River 

 series, Ribstone Creek (T. 0. W.) ; west of Medicine Hat (J. W. D.) 



Sequoia. — Type of S. sempervirens, the "Redwood" of California. Wood with 

 wide, woody fibres, having usually small, bordered pores in two series. Medullary rays, 

 simple or complex, of many rows of cells superimposed ; distinct resin tubes. Belly River 

 series, Ribstone Creek (J. B. T.) ; Belly River series, white rocks above coal bank (T. C. W.), 

 three specimens ; Saskatchewan River (Dr. Selwyn.) 



