NEW SPECIES FOSSIL CONIFEROUS WOOD. 



The average size is of course much less, being about .07""" in loug, and 

 .03 to .O. - )""" in short, diameter. The medullary rays are observed to be 

 aumerous. The largest cells are in contact with the medullary rays. 



Radial section.— The wood cells or tracheids appear broad and thick- 

 walled in this section, and to be provided with two rows of very large 

 pits which nearly touch in the center, and are in contact with the walls 

 on the outside. The diameter of the onter circle is .020 ,nm , that of the 

 inner .0040 to .0000""". They are rarely in a single row when they oc- 

 cupy the center of the cell. 



The resin-ducts consist of a chain of short cells the contents of which 

 are not preserved. 



Medullary rays abundant; individual cells long, covering the width 

 of six or eight tracheids; thin-walled. They seem not to have been 

 provided with pits or markings. 



Tangential section.— Medullary rays in a single series, and rarely, of 

 1-41 superimposed cells. It is not common to find rays with less than 

 5 cells or more than 30, the average being about 10 to 25. Xo pits on 

 the walls of the tracheids. 



The single specimen upon which this species is founded was collected 

 by Mr. Glasgow from « a log 30 feet long in clayey soil."* It is the 

 ordinary silicified wood so common from this part of the country. Its 

 age is, without doubt, Laramie, as it is not far from Gleudive, from 

 which come typical Laramie plants. 



As in the case of the species first described, this species has affini- 

 ties with forms already described from Russia and elsewhere, but the 

 differences are such as to entitle it to specific distinction. 



EXPLANATION OF PLATES. 



Plate It. 



Figs. 1-5. Cupreseinoxylon GUsgowi, n. sp. From Emmet County, Iowa. 



Fig. 1. Radial section, x 90. a, Dense fall- wood; h, large-celled spring-wood 



d .shows ready separation of spring and fall wood. 

 Fio. -J. Transverse section, x 90. a, Spring-wood; b, fall-wood? e, summer- 

 wood; d, single medullary ray. 

 En;. :!. Tangential section, x 90. 



Ik;. 1. Radial section through resin-duct, a, Resin in duct. 

 Fig. 5. Radial section, x 310. Single tracheid, showing arrangement of pits. 



Plate III. 



Figs. 1-4. Cupressinoxylonelongatum, n.sp. From Tiger Buttes, Dawson Conn ty, Mont 

 bIG. 1. Radial section, X 90. «, Resin-duct. 

 FlG. 2. Tangential section, x 90. 



Fig. 3. Radial section, x 310. showing the arrangement of pits. 

 FIG. 4. Transverse section, x 90. a, Cells of spring-wood; b, cells of .snmmer- 

 wood: c. cells of fall- wood ; c, medullary ray. 



* In letter of McGee, September II. ls-7. 





