FLORA OK THE TKLMTY FOK.MATION. 329 



Mr. Iiohoi't T. Hill, who had had Ihc advaiitajic of a numbor of years' 

 resideiK'O in Toxas, studied its <ie()lo,t!;\' with <:;i'ea1 cai'e and worked 

 out the sti'atigraphical relations of the heds with much greater exact- 

 ness than any of his ])i'edeeessors. To him. in fact, we are indebted 

 for the first cori-ect section. After joinini;; the stati' of the United States 

 Geolofiical Sui'V(>y as chief assistant to Di'. (". A. White, his woi'k was 

 verified Ijy the latter, who went personally over the ground. 



In Fel)ruai'y, 1SS7, Doctor White published a paper" givinp; the results 

 arrived at so fai- as the Ci-etaceous was concerned. In the section given 

 on page 40 of that paper the Comanche series is recognized and the 

 lowest bed is called the ''Dinosaiu' sands." It is describcMJ by Mr. Hill, 

 who, as Doctor White states, wrote "the remarks at the right-hand 

 side of the column," as ''coarse silicious sand, popularly called "pack- 

 sand." Occiu's l)etween the Ijase of the fossiliferous Cretaceous and the 

 Carl;)oniferous series. Contains vertebrate remains." 



In April of the same year appeared Mr. Hill's paper '' on the Cross 

 Timbers, w'ith his own nuich fuller section of the Cretaceous of Texas 

 (pp. 298-299). It is the same in its more general features as the sec- 

 tion given in Doctor White's paper, except that Shumard's name "Austin 

 limestone" is substituted for the name Dallas limestone; but much 

 fuller historical, stratigraphical, and paleontological data are here given. 

 The term "Dinosaur sand" is still retained for the basal beds representing 

 the Upper Cross Timbers. The Lower Cross Timbers are shown to occupy 

 a belt at the base of the Upper Cretaceous, which, therefore, practically 

 corresponds to the Dakota formation. In these sections the whole of the 

 Comanche series is shown to be Lower Cretaceous and the basal sands 

 to be at the boundary line between the Cretaceous and the Jurassic. 



Six months later Mr. Hill published a second papei' on the Texas 

 Cretaceous,' further discussing the stratigraphical relations. On pages 

 305-306 of this paper he sa^'s : 



The basal or Dinosaur sands of my section, which are interpolated between 

 the Fredericksburg division and the undoubted Carboniferous, are the shore detritus 



" On the Cretaceous formalion.s of Texas and tlieir relation to those of other portions of North Ameriea, 

 l)y Charles A. White: Proe. Acad. .Nat. Sei. of Philadelphia, 1.SS7, pp. .39-47. 



'' The topography and geology of the Cross Tirnhers and surrounding regions in Northern Texas, hy Kohert 

 T. Hill: Am. Journ. Sei., .3d ser., Vol. XXXIII, April, 11SS7, i)p. 291-.303. pi. vi (map). 



''■ The Texas section of the American Cretaceous, by Rohert T. 11 ill; .\Mi..Iourii. Sei., 3d ser..A'ol. X.XXIV, 

 Oetoher, 1887, pp. 287-.309. 



