210 ANATOMY OF THE GYMNOSPERMS 



Radial. Medullary rays very low, the cells straight, about 1 7 fj. high, equal 

 to about 5 tracheids ; the upper and lower walls thin and not pitted ; 

 the terminal walls thin, straight, and devoid of pits ; the lateral walls 

 with large (?) pits, i per tracheid. Bordered pits on the radial walls of 

 the tracheids not recognizable. 



Tangential. Medullary rays 1-3, more rarely 4, cells high, about 8.7 p. 

 broad. 



Material calcined. 



Upper Cretaceous of Port McNeil, Vancouver Island, and Upper Creta- 

 ceous of Cumshava Inlet, Queen Charlotte Islands. 



III. CONIFERALES 



Wood more or less resinous, often characterized by the presence of 

 specialized resin cells, cysts, or passages. Tracheids (transverse) in radial 

 rows, bearing on their radial walls, as also on the tangential walls of the sum- 

 mer tracheids, round or elliptical, often distant, bordered pits in 1-3 series. 



1. TORREYA, ARNOTT. PLATES 20 AND 21 



Transverse. Growth rings rather thin, often variable ; tracheids rather 

 large, chiefly squarish, the structure generally open throughout. Sum- 

 mer wood usually very thin. Resin cells and resin passages wholly 

 wanting. 



Radial. Ray cells very long, the tracheids of the wood with rather open 

 spirals in 2-4 series. 



Tangential. Ray cells large, broadly oval or oblong. Fusiform rays wholly 

 wanting. 



SYNOPSIS OF SPECIES 



A. Summer wood thin, of 2-4 tracheids or more, often double ; the 

 structure of the growth ring very open throughout 



Tracheids large, distinctly squarish. 

 Spirals in 2 series. 



1. T. taxifolia. 



B. Summer wood thin but sometimes equal to the spring wood 



Tracheids very unequal, not conspicuously squarish, chiefly hexagonal, 

 often in very irregular rows. 



Spirals imperfectly 2-4 seriate, often very incomplete. 



2. T. californica. 

 Spirals in double, triple, or quadruple series. 



3. T. nucifera. 



