CORDAITES 201 



6. C. illinoisense, Dn. 



Transverse. Tracheids 47x47^ broad, the walls 9.3 p. thick. 



Radial. Ray cells straight or abruptly narrowed at the ends, equal to 3-4 



tracheids ; the lateral walls show no recognizable structure. Bordered 



pits in 1-3, chiefly 2, rows, hexagonal, 12.5 p. broad. 

 Tangential. Rays numerous, i-seriate or 2-seriate in part, the broadly oval, 



thin-walled cells 28 p. broad. 



Chase Formation (Permian) of Chase County, Kansas ; the Coal Measures of 

 Rock Island, Illinois, and Boonsboro, Iowa (?). 



7. C. materioide, Dn. 



Transverse. Tracheids about 56x56 p. broad, the walls 12.5 p. thick. 



Scattering tracheids contain resin. 

 Radial. Ray cells straight or somewhat contracted at the ends ; the pits on 



the lateral walls oval, narrowly bordered, i-S, chiefly 2-3, per tracheid ; 



the lenticular or oblong orifice nearly equal to the diameter of the pit. 



Bordered pits hexagonal, in 1-3, chiefly 2, rows. 

 Tangential. Rays i-seriate or sometimes 2-seriate in part, upwards of 35 cells 



high; the oval or round cells 25-31 p. broad. 



Douglas Mine, Grand Lake, and Mirimichi, New Brunswick ; Port Hood and 

 Mabou, Cape Breton; Joggins, Nova Scotia. 



8. C. annulatum, Dn. 



Transverse. Structure much altered by decay, extensive areas being com- 

 pletely carbonized and consolidated to coal. The tracheids are about 

 34 x 44 p, broad, the walls much attenuated by decay. 



Radial. Structure of the rays not determinable. Bordered pits hexagonal, 

 9.5 p. broad, in 2-3, chiefly 2, rows. 



Tangential. The structure is too much altered by decay and pressure to 

 make the details obvious. 



Middle Carboniferous, Joggins, Nova Scotia 



9. C. ouangondianum, Dn. 



Transverse. Tracheids about 47x56^ broad, the walls 9.3 p, thick. Growth 



rings none. 

 Radial. Bordered pits numerous throughout the tracheids, in 2-4, chiefly 3, 



rows, about 12 p. broad. Ray cells equal to about 3-4 tracheids; the 



lateral walls with oval pits, 2-4, chiefly 4, per tracheid and disposed in 



radial series. 

 Tangential. Rays of medium height, i-seriate or 2-seriate in part, the oval 



cells chiefly about 25-37 p. broad. 



Middle Devonian of New Brunswick. 



