PLATF. XVI. 



Page. 

 Figures l-o. Cupressi'noxylon calU Knowllon from [xiiut 5} miles iKirtli nf (Kiinosvillo, Ark 174 



1. Trausvorso section showing a modullary luy. 



2. Same, p;issiiig tlirouj;li a growth ring, 

 o. Uadial section showing l)ordere(l pits. 



4. Same, showing ])its on niiMhilhiry rays. 



5. Radial section showing chain of re.'^in cells. 



Figures (i-li). Laurinoxi/lon branneri Knowlton from vicinity of Harrisbnrg, Ark 314 



(i. Tangential section showing large reticulate-thickened duct and ra)-s in two series. 



7. Transverse section showing arrangement of ducts and rays. 



8. Radial section showing ducts and large medullan,- rays, wood cells not well preser\-ed. 



9. Tangential section showing reticulate thickening of tangential walls of ducts. 



10. Radial section showing pitting on radial walls of d\ict.s. 



50243°— 16 25 ^ 365 



