36 ROYAL SOCIETY OF CANADA 



Taxodium distichum, Eich. 



Fig. 1. 



Eocene of the Great Valley and Porcupine Creek Groups; North Saskatche- 

 wan; Souris River; Red Deer River; Elko Station, Nevada; Evans- 

 ton; Alaska? Carbon? 



Miocene of the Similkameen River; Horse-Ply River, B.C.; John Day Valley, 

 Oregon. 



Bib. :— Trans. R. Soc. Can., VIII., iv., 1902, 51, 68. 



Transverse. — Growth rings rather broad, the structure much altered by decay 

 and pressure; the spring wood compressed to an angle of 45 degrees 

 and details obliterated. Summer wood dense, very variable in thick- 

 ness, the transition from the spring wood abrupt. Medullary rays 

 resinous, conspicuous. Resin canals wholly wanting. Resin cells 

 numerous and prominent; in the spring wood with dark- resin 

 masses, normally in tangential bands; in the summer wood fre- 

 quently in tangential bands, chiefly appearing devoid of resin 

 masses. 



Radial. — Ray cells of one kind only, the walls thick when not reduced by- 

 decay; the terminal walls thin, straight or curved; the lateral walls 

 with bordered pits 1-2 per tracheid, when of the latter number in 

 radial series, oval or round, the lenticular-oblong orifice diagonal to 

 the cell axis. 



Tangential. — Rays rather high, all of one kind and uniseriate; the cells broadly 

 oval. 



Among the woods sectioned lor the first (?) time was one which 

 cannot be identified with any of the descriptions or figures given by 

 Sir William Dawson, and it is thus possible that it escaped his notice 

 altogether. On the other hand, the original hand specimen may ha.ve 

 been lost, and this alternative is suggested by certain references to 

 be noted later. The wood had evidently been subjected to extended 

 decay, while it was subsequently brought under the influence of pres- 

 sure whereby secondary alterations were developed. That the wood 

 was also one which offered a high degree of resistance to decay is 

 likewise apparent in the special character of the alterations effected. 

 In the transverse section the very strongly developed summer wood 

 has been so far altered that the secondary layers of the thick walls are 

 greatly swollen so as to nearly obliterate the cell cavities and thereby 

 'destroy essential features of structure. ISTevertheless, it i> quite pos- 

 sible to readily establish the point of contact with the spring wood 

 because of the lateral compression which, following decay, has forced 

 the lines of structure over to an angle of about forty-five degrees to 

 the normal. The medullary rays are very prominent and they may 

 be readily followed throughout their entire course by reason of the 



