4 NEW SPECIES OF FOSSIL WOOD. 



perfectly round, small pores ; medullary rays numerous, compose! 

 single series of 1-22 short, superimposed cells; resin duets 

 (PI. I, figs, 1-5.) 



Transverse section,— The cells in this section are observed to 1 

 indicated above, moderately thick walled, and to be separated by 

 intercellular spaces. The largest cells observed have a dku.iel 

 .055™ and the smallest of about .020"-, theaverage being about .o! 

 Radial section.— As seen in this section the tracheids are observ 

 be long, and to be provided with numerous pores. These pon 

 bordered pits are usually arranged iu a single linear series and 

 ber from 40 to 80 or more on each cell. (Fig. 4.) I'sually they t 

 each other slightly, but sometimes, as indicated in Plate I, 6gd 

 they become a trifle compressed by actual contact. When tliesepor* 

 arranged in two series, as illustrated in Plate i, figure 5 tliey altes 

 and are slightly, if at all, angled by mutual pressure. ' The pore 

 rather large, the average diameter for the outer circle bein- a 

 .02""", that for the inner .0040'"'". 



The medullary rays are composed of short, thin-walled cells wl 

 rn some instances, seem to have been provided with small oval pi 

 Ihey are difficult of demonstration, and it is possible that the grat) 

 contents of the cells may give the appearance of exterior marking 

 Tangential ^ c //o».-This section demonstrates the presence of | 

 or bordered pits on the tangential walls, a circumstance of iufreq. 

 occurrence m the genus Araucarioxylon. They are much smaller 1 

 the pores on the radial walls, and are in a single or rarely in two se 

 1 he pores are always separated from each other, sometimes widely 

 the diameter of the outer circle is about .0075""" and that of the ii 

 is about .0027""". 



The medullary rays are numerous and range in height from 1 t< 

 cells. It is possible that in some rare cases thev may be in two sei 

 but this is certainly not commonly the case. 



Xo resin ducts have been detected in any of the sections, their 

 sence being a well-known character of the genus. 



An examination of the literature of the subject shows relationship 

 tween tins and several described species. Thus Araucariowy Ion 1 

 ****** (Gopp.), Kraus (see Goppert, Mouog. d. foss. Couif. p. 235, 

 klv, figs. 0, ,, and Foss. Pi. d . perm. Form. p. 250, PI. lvii, figs. 1 

 a sveli-known species from tlie Permian of Silesia, very much resemb 

 it, yet there are minor points of difference in the histological elemei 

 as well as the great difference in the geological and geographical p< 

 ' ion. bo also w,th A. wgesiacum Kraus, ,1. Thuringicum Kraus, A. 

 Uinumum Ivnowltou, MS., and others. 



