STRATIGRAPHICAL GEOLOGY 
155 
names. It might be questioned whether, without something more 
than a few weeks’ field work, the stratigraphic features of so vast 
an area may be advantageously made the subject of generalization, 
or whether even serial correlation is worth while. It is certainly 
difficult, at a distance to harmonize the various desultory and scat¬ 
tered records, and to weave them into a connected fabric without 
long familiarity in this field. 
The so-called Bernalillo shales, comprising the Abo red beds 
and the Yeso pink beds, immediately overlying the great lime¬ 
stones of the Sandia mountains, are recognized as belonging to 
the Pennsylvanian system, as Herrick and others long ago set 
forth, and not to the Jurassic-Triassic as the Federal Survey has 
heretofore always contended. The great Maderan limestone is 
regarded as a compact stratigraphic unit. No red beds of Triassic 
age are now thought to be represented in the Rio Grande valley; 
the full evidence of this conclusion had been stated several years 
before. 
\ 
Less happily chosen and far from convincing are the various 
stratigraphic correlations and the correlations of the geologic sec¬ 
tions already published. At times the manifest mis-statement of 
the views and observations of early writers on the region ap¬ 
proaches perilously close to carelessness, to say the least. To 
those already at all familiar with the geology of the region and to 
those who in the future shall become familiar with it, it must often 
appear that the correlations made can be only too frequently purely 
gratuitous. Many instances might be cited. Complete lack of 
presentation of critical data upon moot points is strongly felt. 
As to the assumed importance of an attempted explanation of the 
stratigraphy in some manner or other it is vastly overestimated, 
largely irrelevant, and, for so broad a field with so limited a time 
to devote to it, better omitted altogether. At least publication 
could well be deferred until the data shall have been digested 
somewhat and the detailed proofs expanded in some other con¬ 
nection. 
The fauna of the Guadalupe Mountains of Trans-Pecos Texas 
and southeastern New Mexico was first made known by Shumard 
more than half a century ago. With his usual paleontologic acu¬ 
men this author determined this fauna to represent that of the 
true Permian of eastern Russia. Shumard’s descriptions were 
