ate 
340 BOTANICAL GAZETTE [APRIL 
from the ‘“‘Chase Formation (Permian) at Coon Creek, Chase Co., 
Kansas, in 1897’ (PENHALLOW 5, p. 76). The type set of sections 
is the property of the Peter Redpath Museum, and through the 
courtesy of the McGill authorities has been put at our disposal for 
study. Itis to be regretted, however, that no more material of the 
specimen from which the sections were prepared can be found.. 
Careful search has been made both at McGill and at Washing- 
ton (U.S. Geological Survey), where Prosser sent his collection. 
The sections are three in number, transverse, radial, and tangen- 
tial. They are labeled ‘‘ Pityoxylon Chasense, 5, Cretaceous," C. S. 
Prosser.”’ Plate figs. 1-3 show these at a lowmagnification. The 
matrix is siliceous, but the material is only ‘“‘fairly well preserved,” 
and though the sections have been excellently made, certain 
important structural features are not determinable. PENHALLOW’S 
description is very brief, and is not illustrated. This renders it 
difficult to correlate it with the sections. 
The transverse section is 12.5 mm. in radial extent, and in that 
distance shows no growth rings, so that it seems probable that these 
are absent or at least poorly developed, as PENHALLOw has stated. 
This feature and the form and arrangement of the tracheids are 
shown in plate fig. 4. The absence of annual rings is not a charac- 
teristic of the genus Pityoxylon of Kraus, and yet in spite of 
this, and in spite of other important features which indicate its 
| cordaitean affinity, PENHALLOw placed this form under that genus, 
\ because of the occurrence of what he considered were horizontal 
resin canals. 
Text fig. 1A illustrates the character of the medullary ray cells in 
radial section. They are four to five times as long as high, and, 
as compared with the tracheids, are thin-walled; the radial extent 
of the latter and the thickness of their walls are indicated by the 
sets of short lines below the parenchyma cells. Many rays were 
examined, but no pits could be found on either the horizontal or 
terminal walls, nor is there any special thickening of these walls, 
features which are characteristic of Pityoxylon. Their structure, 
on the contrary, is of the characteristic cordaitean or Araucarioxylon 
type. 
I There would seem to have been an error in labeling these “Cretaceous,” since the 
Chase formation is Permian, as PENHALLOW himself has stated in his description. 
