818 Ff. W. CRAGIN 
in north-central Texas and which is especially abundant in 
Hamilton county of that state. Specimens of both species, as 
usually preserved, vary somewhat in shape owing to mechanical 
distortion, and it is difficult to determine their precise natural 
form. Apparently, however, the Malone species differs from 
the P. henseft in having its posterior portion less tapering and a 
little recurved. The ammonite fragment did not show the 
suture; but the form and ribbing indicate a type common in the 
upper Jurassic. 
As shown by the the rock adhering to fossils in the Goodell 
collection, the fossiliferous strata of the Malone hills consist in 
part of hard yellowish to brownish gray calcareous sandstone or 
arenaceous limestone. The sandy component is largely the 
débris of acidic eruptive rocks of undetermined varieties. But 
it seems probable that the massive, calcite-seamed limestone and 
the gypsum occurring in the more westerly part of the same 
hills and across which Mr. Robert W. Goodell’s section was 
taken, are closely associated and should be referred to the same 
formation with them ; and ifso the similar gypsums and massive 
limestones of Malone Mountain, described by Mr. Taff as the 
Malone formation (which in several respects the Goodell section 
duplicates), is a prominent part of that formation. For the 
formation, therefore, provisionally regarded as embracing the 
fossiliferous sandstones and limestones, the gypsums, the massive 
calcite-seamed limestones, and any other rocks included among 
these, of the Malone Mountain and the hills north and east of 
Malone Station, Mr. Taff’s name Walone beds, or Malone for- 
mation is appropriately retained. The Malone formation thus 
assumes wider limits, a different age-significance, and far greater 
importance than were assigned to it by Mr. Taff. Yet to him 
belongs the credit of having published the first section from it, 
and of having called attention to the fact that the Malone uplift 
is older than other orographic features of the Sierra Blanca dis- 
trict 
The Geological Map of Mexico, published by the late Direc- 
tor of the Geological Survey of Mexico, Sefior Castillo, shows a 
