814 C. H. GORDON 
work has been done, and the names applied to different formations 
have been in some cases not at all defined, while in others the descrip- 
tions can be interpreted only with the greatest difficulty. A few names, 
however, are well established. Herrick! applied the name Sandia 
beds, or Sandia series, to the alternation of shale, limestone, and sand- 
stone which constitute the lower half of the Magdalena division in 
Socorro and Bernalillo counties in 1900, and his description is such 
that no difficulty is encountered in the application of this term. At 
the base of the formations east of Socorro is a bed of clay containing 
Carboniferous plants to which Herrick gave the name Incarnacion 
Fire Clay, but he expressly states, ‘There would seem to be no reason 
for separating the fire clay from the Sandia formation, it being but a 
local variation.’’? 
The limestone formation overlying the Sandia beds he appears to 
have left unnamed, but to the bed of sandstone which occurs near the 
middle of the formation in the vicinity of Coyote Springs, Bernalillo 
County, he gave the name Coyote sandstone. 
The same author applied the name Manzano‘ to the series of 
red sandstone and other beds which overlie the rocks of the Magdalena 
division in the Manzano Mountains and adjacent regions. His 
description of these beds does not make it altogether clear whether 
he meant to apply the name to the lower red sandstone alone or to 
the whole series, including the gypsiferous beds, the chocolate-colored 
sandstones, and their accompanying shales and earthy limestones. 
It would seem, however, that the latter was his intention. He does 
not seem to have included under this name the limestone overlying 
the pink and yellow sandstones, which, as shown by Lee,’ belong in 
the series. 
In a recent; paper, ©. R: Keyes® presents a classification of the 
Carboniferous rocks of New Mexico in which several new names 
appear, but without adequate definition. The shale bed at the base 
of the Sandia formation he separates, giving it the name Alamito, and 
tC. L. Herrick, Jour. Geol., Vol. VIII, p. 115, 1900; Am. Geol., Vol. XXV, p. 235, 
1900; tbid., Vol. XII, pp. 237-251, 1904. 
2 Jour. Geol., Vol. XII, p. 242, 1904. 3 Jour. Geol., Vol. VIII, p. 115, 1900. 
4 Loc. cit. 5 W. T. Lee, Jour. Geol., Vol. XV, pp. 53, 54, 1907- 
6C. R. Keyes, Jour. Geol., Vol. XIV, pp. 147-54, 1906. 
