224 =C. D. Walcott— Permian, ete. Groups of Arizona. 
Howell, oat the Shinarump conglomerate in Southwestern 
ah. y belong to a species distinct from P. asteriscus of 
the Fucraceh Three species are now known to pass from the 
lower division to the limestone of the upper division. 
mian character of the fauna, taken with the evidence 
afforded by the stratigraphy, clearly establishes the Permian as 
a well-defined and distinct group in the Colorado Valley. It 
occurs at the same horizon as the Permian determined by Mr. 
Clarence King in Northern Dia, Western Colorado, a South- 
ern Wyoming, fully corroborating the views advance him 
of the age of the beds resting on the “ Bellerophon wadk ” of the 
Upper Carboniferous.* 
The Permian as found in the Kanab section undoubtedly 
extends to the west, east and southeast in Arizona and New 
Mexico.t 
Mr. Jules Marcou referred the beds resting on the Carbonif- 
erous at the crossing of the Little Colorado to the Permian. 
He says:}t ‘This formation, which is placed between the Car- 
boniferous and the T'rias, corresponds without doubt, to the 
magnesian limestone [Permian] of England.” The proof of this 
was entirely stratigraphical, but Mr. Marvin’s discovery of Per- 
mo-carboniferous fossils at the same horizon and locality, and 
on the same horizon of those obtained by Mr. Gilbert, which 
are known to have come from the lower division of the Per- 
mian, as given in the present note, tends to prove that Mr. 
Marcou was correct in his original reference of the beds he 
mentioned to the Permian and entitles him to the claim he as- 
serts of adding a new member to the sites of secondary rocks 
in North America, although, pe ane! ne includes a portion 
of the Upper Aubry group in his Per 
is of the Coal-measure type, except near the base, where there 
is an assemblage of forms uniting a few coal-measure species 
me a much larger proportion of a Lower Carboniferous char- 
acte 
The Carboniferous rests on the sonra erate surface of the 
Devonian formation. The Devonian beds very variable in 
character, and of little vertical eis At Massie greatest devel- 
opment, when increased by being deposited i in a hollow of the 
limestone beneath, there is but 100 feet of purple and cream- 
colored limestone and sandstone passing into gray calciferous 
sandstone above. Over the knolls of Silurian limestone the 
* ee of the 40th Parallel, i, pp. 245, 246, and atlas maps of the 
Newberry, Shumard, Gilbert, Marvin and Howell all. “ 
information of this horizon. 
t Pacific R. R. Report III, pt. iv. Resumé, p. 170. 
