WARD.) FOSSIL WOOD FROM THE JURASSIC. 419 
not the same as in what may be called typical wood of the genus; that 
is, they are not in the least hexagonal. The latter feature, however, 
is somewhat variable, and for the present it seems best to place this 
wood in Araucarioxylon. 
This species resembles in some particulars several of the described 
species of the genus in this country. Thus it has the same type of 
tracheids and medullary rays as A. wirginianwm Kn., but has the 
bordered pits quite unlike that species. On the other hand, the pits 
are quite similar to those found in A. Woodworth: Kn., of the Triassic 
of Virginia and North Carolina, but the medullary rays are entirely 
different. From A. arizonicwn Kn. the species under consideration, 
which agrees somewhat in the character of the bordered pits, differs 
in having the ray cells very long instead of short, and further in the 
absence of pits on the tangential walls of the tracheids. The character 
of the rays as shown in transverse section is quite similar in all of 
these species. 
Locality.—Cycad bed, Freezeout Hills, Carbon County, Wyoming. 
Collected by W. H. Reed. 
FOSSIL WOOD FROM THE JURASSIC OF THE BLACK HILLS, 
Prof. W. P. Jenney sent a few very imperfectly preserved speci- 
mens of fossil wood from his bed No. 5 of the Hay Creek region of 
Crook County, Wyoming, in the Black Hills, and noted its occurrence 
in that bed in the ample notes that accompanied his collection.* 
When I was in the Black Hills in October, 1898, Mr. H. F. Wells 
informed me that he found it frequently in the pink and white sands 
that overlie the Atlantosaurus beds, and he took me to one locality 
near his house, three or four miles northwest of Sturgis, South Dakota, 
where beds of carbonaceous shales containing lignite are overlain by 
sands in which silicified wood occurs in great quantities and in a per- 
fect state of preservation. I brought away one specimen which shows 
the annual rings more distinctly than any other fossil wood I have 
ever seen. This Dr. Knowlton also consented to treat microscopically 
for this paper. When'I obtained it I had no doubt of the Jurassic 
age of the bed in which it occurred, but Dr. Knowlton finds the inter- 
nal structure very modern in character, scarcely distinguishable from 
that of Pinus except in the absence of fusiform rays. I hesitate, there- 
fore, to assert that the age is certainly Jurassic, and reserve my final 
decision on this point until a more thorough investigation can be made 
than was possible at the time I was there. Still, I think there was no 
mistake, and that this specimen simply represents a Jurassic ancestor 
of Pinus which has persisted to the present day with little modifica- 
tion. Dr. Knowlton proposes for it the name Pinoxylon, as a new 
genus, this name not having been used, so far as we can learn. 
1§ee Nineteenth Ann. Rept. U.S. Geol. Survey, Pt. II, pp. 573, 589, fig. 122 facing p. 593. 
