[pENHALLow] NORTH AMERICAN SPECIKS OF DADOXYLON 78 



In a radinlly longitudinal section, the inner bark consists of verti- 

 cally elongated pa>roncliynia elements, and it is penetrated throughoat 

 by narrow rosin cells which accumulate en its outer face, become in- 

 dividually l)r()a(k'r and form a zone 2-3 layers thick (fig. 5 and 6). 

 The resin canals ai)pear to be devoid of transverse septa, and are always 

 full of resinous matter in a more or less granular form. 



In ihe middle l>ark the piirenchyma elements are radially elongated 

 as in the transverse section, and the structure is penehuted by numerous 

 resin canals which traverse the tissue in a direction chiefly coinciding 

 with tlie axis of growth, but ^.is they branch, they often become trans- 

 verse or partially so. (Fig. 7). 



TransrtTsc— Tracheids very variable, growth rings obscure. 

 liadial. — Structure of the medullary rays rcc determinable. 



Bordered pits hexagonal, in two rows throughout. 

 Tangc7itial.— Ray a numerous and variable, 31-57 mic. broad; the cells very 



variable in form and size, thin walled, often broader than high. 



chiefly 1-seriate, often more or less 2-seriate. 



CoRDAiTES ncNxsYLVAXici-M, Dn., n. sp. 



An unrecorded species collected by, Dr. Newberry from the Car- 

 boniferous at Pittsville, Pa. 



7Va«sm-sc.— Tracheids 44 x 44 mic. broad, the walls 6.7 mic. thick. Growth 

 rings present, the summer wood about S tracueids thick, the 

 tracheids about 12.5 mic. radially, the walls 3.1 mic. thick. Resin 

 passages and resin cells wanting. 



Radial.— Ray cells all of one kind, conspicu isly but gradually narrower 

 toward the ends, equal to about 3 tracheids; the lateral walls with 

 round or oval pits, about 2-3 per tracheid. 



Tangential— Rays medium, broad, the cells round or transversely oval, vari- 

 able, 25-31 mic. broad. 



COHDAITES niX'KNTirM, Du., n. ,<[). 



An undescribed species from the Permian or Permo-Carboniferous 

 of Prince Fxlward Island. This was regarded by Sir William Dawson 

 las being closely related to V. materiarium, if not identical with it. The 

 characters, however, are such as to nuirk it off as a distinct species. 



r;ansr(7-6T.— Tracheids 47 x 5? mic. broad, the walls much reduced by decay. 

 liadiaL— Ray cells all of c e kind, about equal to 2 tracheids; the lateral 



walls with round pits about 1 (?) per tracheid; the cells conspicuously 



narrower at the ends. 



