■76 KOYAL SOCIETY OF CANADA 



PiTYOXYLON CIIASEXSE, 11. Sp. 



This material was obtained by Prof. Prosser from the Cliase Forma- 

 tion (Permian) at Coon Creek, Chase Co., Kansas, in 1897. The 

 structure is fairly well presen-ed. Its cliief feature is to be found 

 in the occurrence of broad rays which bear a small, central resin canal. 

 This feiature is exhibited by my sections in tangential section only, pro- 

 bably in consequence of the special condition of preservation. It 

 nevertheless sen-es to definitely separate the plant from Cordaites, and 

 its aliinities are rather with tlio Pityoxylon of Kraus.^ 



Transverse. — Tracheids chiefly in regular radial rows, very variable in size, 



squarish, about 44x44 mic. broad; the walls 12.5 mic. thick. 



Medullary rays numerous, chiefly one cell wide, occasionally 2-3 



seriate. Growth rings wholly wanting. Resin cells and resin 



canals not represented. 

 Ra(Ji(iI.~Ra.y cells all of one kind; straight, equal to 2-4 tracheids; the upper 



and lower walls thin and not pitted; the terminal walls thin, not 



pitted, straight or (jurved; the structure of the lateral walls not 



determinable, but the pits are probably round. 



Bordered pits in 1-3 rows, chiefly 2 rows, round or hexagonal, 



12.5 mic. broad, the orifice probably round. 

 Tangential.— Ra.y3 of two kinds. 



(1) Uniseriate rays, the cells oblong, 25 mic. broad, often 2-seriate 

 in part. 



(2) Fusiform rays, the terminals linear and of the structure of 

 the uniseriate rays; the central tract very broad, nearly round; the 

 cells large, thin-walled, irregular and enclosing a small, central 

 resin passage with large epithelium cells. 



CUPRESSIXOXYLON CHEYEXXENSE, n. sp. 



A specimen of the Prosser collection obtained from the Cheyenne 

 (Comanche Cretaceous), east of Stokes Hill, Kiowa and Baker Co. line, 

 Kansas, 1897. 



7'/((//,s(«/-.sc.— Tracheids in regular, radial rows, rather uniform, roundish, 



about G2x62 mic. broad; the walls 15.5 mic. thick. 



Resin passages and special resin cells wanting. 



Growth rings apparent, very broad, in a radial extent of 20 mm., 



two growth rings of an equal thickness of 10 mm. are represented. 



The summer wood conspicuous, about 3-4 cells thick, the tracheids 



about 29 X 38 mic. broad, the tangential walls about 15.5 mic. thick. 



Radial— Ra.y cells all of one kind, straight; the upper and lower walls thin 



and not pitted; the terminal walls thin and not pitted, straight or 



' Schimper, Pal. Veg., 370. 



