C. J, Hylander — Mid-Devonian Callixylon. 315 



Aet. XXX. — A Mid-Devonian Callixylon; by C. J. 



Hylander. 



In the paleobotanical collections of Yale University 

 there have long been some nnstudied sections of a 

 Devonian wood from Eighteen Mile Creek, New York. 

 These sections were made by Dr. Wieland abont 1900, 

 from material collected by 0. C. Marsh in 1860. They 

 bear numbers 240, 241, and 242. Since this wood con- 

 sists merely in siliceous fragments containing much 

 residual carbon, and is otherwise poorly preserved, the 

 structure is difficult to make out. Only the transverse 

 and radial longitudinal sections are diagnostic. The 

 tangential section failed, cutting a region of especially 

 poor preservation, with oblique compression. 



Nevertheless, a new species of Zalessky's genus Cal- 

 lixylon (7) 1 is indicated, and attention to the plants 

 rather than associated vertebrates must bring to light 

 better material of the original stem type, supposedly a 

 foot or more in diameter. If so, further sectioning must 

 disclose the better conserved areas as in various other 

 instances of petrified stems. Accordingly, it has been 

 considered worth while to give the description which 

 follows. The value of these notes rests in the fact also, 

 that the fine type from the Indiana Black Shale, Cal- 

 lixylon Oweni (6), is at hand for close comparison and 

 renders less doubtful features that otherwise would be 

 obscure. The camera lucida figures here reproduced are 

 accurate to scale, and are not restored, but actual 

 drawings of the areas they show. 



Generic Position. 



The grouping of the radial pits in discontinuous masses 

 undoubtedly puts the wood of these sections into the 

 genus Callixylon. Other characters also are those of 

 typical Cordaiteah wood, as described by Penhallow (5), 

 or Elkins & Wieland (3). In regard to the specimens 

 and their inclusion in Zalessky's genus, Dr. Wieland has 

 the following to say : 



1 For Literature references see the end of this paper. 



