Record oe Geology of Texas, ISS'Z-ISUO. 
263 
White, Charles A. 
Intimate association of these two formations in the region of the Lower 
Rio Grrande. No evidence at present of the Laramie in Webb and Maver- 
ick counties. The coal found there belongs to the equivalent of the Fox 
'Hills group. The mines at San Tomas, forty miles above Laredo, and those 
seven miles above Eagle 'Pass are the principal 'ones on the Texas side, 
iln Mexico the equivalent of the latter coal is found a few miles from] 
Piedras Negras. From data furnished by Mr. James T. Gardiner, it was 
ascertained that the Laramie and Fox Hills formations exist in the State 
of Nuevo Leon and the eastern part of the State of lOoahuila. Both of 
these formations were found by the writer (White) in the region of 
■Coahuila drained by the Rio Sabinas. 
Little is known of the character of the coal deposits in the southern part 
of Presidio and El Paso counties, Texas. 
422. 
On Generic Forms of Cretaceons Mollnsca and t'heir Rela- 
tion to Other Forms. 
Proc. Acad, of hlat. Sci., Phila., Pt. I, pp. 32-37; pi. II. 
Jan. -Apr., 1887 
“The type species of the three generic forms which are described in this 
article belong to the collections of Cretaceous fossils from Texas, which I 
am now preparing for publication in one of the memoirs of the U. S. 
Geological 'Survey. In their generic characteristics all three of them 
appear to be respectively identical with certain forms wbich have long 
been known, but which have been referred to other genera by different 
authors. The features which I now present as having generic value seem 
to have been overlooked by those authors, or, so far as they were observed, 
they were treated as specific characters. Two of these forms belong to 
the section Melininae of the family Avioulidae. The other is referred to 
the Crassatellidae, but it departs considerably from the typical section of 
that family.” 
Crassatellidae. Genus Stearnsia (gen. nov.). Stearnsia Robinsi (sp. 
nov.). Aviculidae. Genus Dalliconeha (gen. nov.). Genius Aguileria (gen. 
nov.). A. Cumminsi (sp. nov.). 
423. ^ — 
On the Cretaceous Formations of Texas, and their Relation to 
those of other Portions of North America. 
Pro'ceedings Acad, of Nat. Sci., Phil., Pt. I, pp. 39-47. Jan.- 
Apr., 1887. 
“The true relations of the different Cretaceous formations which have 
long been known to exist within the iState of Texas to each other, and to 
those which have been recognized in other portions of North America, have 
not hitherto been satisfactorily known. 'Several eminent geologists have 
written upon the subject, and considerable diversity of opinion has pre- 
vailed among them. The former impracticability of obtaining informa- 
tion by personal observation over any considerable portion of that region; 
