Elkins and Wieland — On Devonian Wood. 



75 



II. Specific Characters (by Dr. Wieland). 



Of the generic identity of Cordaites Newberryi and the 

 Indiana form before us we rest assured since the larger charac- 

 ters are the same, and in the specialized feature of tracheidal 

 pit groups both closely agree. Both then are clearly of the 

 same genus, but must represent distinct species, since in the 

 material studied by Penh allow growth rings are not present in 

 a radial extent of 17 mm , while in the Indiana specimen there 

 occur in the same distance six growth rings which could not be 

 overlooked even in a cursory examination. Taking the growth 

 rings as a basis of classification and relying upon the accuracy 

 of Penhallow's description, the main features of these species 

 may therefore be tabulated thus : 



Comparison of Cordaites Newberry i and the Indiana Species. 

 Callixylon (Cordaites) Newberryi Callixylon Oiveni 



Transverse 



Traeheids 44 x 55 mic. 



Walls about 125 mic. thick. 



In a radial extent of 17 mm no evi- 

 dence of growth rings (obscure or 

 obsolete). 



Traeheids conspicuously squarish, 

 sometimes unequal in the two 

 diameters. 



Traeheids 45-60 x 45-60 mic. 

 Walls about 5±mic. thick. 

 In a radial extent of 15 mm 6 growth 

 rings. 



Traeheids 

 round. 



squarish, sometimes 



Kay cells distinct because of con- 

 tents. 



Eadial 



Eay cells resinous and starch-bear- 

 ing, long and narrow, about equal 

 to 3-7 traeheids, ends conspicu- 

 ously narrower, the pits on the 

 lateral walls 3-6, chiefly 4 per 

 tracheid, the slit-like orifice nearly 

 the full diameter of the pit. 



Bordered pits numerous, round, 

 about 9 3 mic. broad, distributed 

 in radially disposed groups of 

 about 6-13, the orifice diagonal, 

 nearly extending the diameter of 

 pit. 



Eay cells often with opaque mate- 

 rial, long and narrow, about equal 

 to 2-8 traeheids, ends not conspic- 

 uously narrower, the pits on the 

 lateral walls usually 6-8 per trach- 

 eid, tbe slit-like orifice nearly the 

 full diameter of the pit, pits sim- 

 ple in the ray cell wall, bordered 

 in the tracheid wall. 



Bordered pits numerous, round or 

 elliptical, distributed in radially 

 disposed groups of 3-40, groups of 

 40 probably double groups, in 1-4 

 vertical rows per tracheid. orifice 

 diagonal, which with the corre- 

 sponding orifice of adjacent trach- 

 eid gives the appearance of a cross. 



Traeheids resinous (?) 



Tangential 



Eays of medium height, 1-2 rarely 

 3-seriate in part, 24-55 mic. broad 

 the oval or round cells all thin 

 walled. 



Eays from 1-40 cells in height, 1-2 

 seriate, never 3-seriate, 30-45 mic. 

 broad, all cells thin walled, oval 

 or round in section, vary in size, 

 most of them contain more or less 

 resinous (?) material with frequent 

 tyloses. 



