22 MESOZOIC FLORAS OF UNITED STATES. 



lower Little Colorado Valley there occur numerous somewhat calcareous 

 clay lenses, the lime taking the form of bright white stripes, while the 

 clay is usually purple or pink. These are very distinct objects and 

 vary in size from lenses 10 or even 20 feet in length to small lenticular 

 blocks or somewhat oval or even spherical clay balls or pellets. These 

 calcareous clay inclusions are scarcely seen farther to the southeast, 

 but on Red Butte they are well marked, and here the clay becomes 

 brilliant red and constitutes a true paint stone. Another fact to be 

 noted in connection with the Lithodendron l^eds is that at certain local- 

 ities, notably on Red Butte, there is at its base a clear indication of a 

 transition to the Moencopie formation. The conglomerates proper are 

 underlain by argillaceous shales closely resembling those of the Moen- 

 copie, iDut beneath these is a sandstone ledge Avhich can not be referred 

 to the lower division, as it is more or less cross-bedded, possesses con- 

 siderable grit, and has included in it small cla}'- pellets similar to those 

 of the true conglomerate series, in which I have for tliis reason included 

 it. This condition of things may be somewhat puzzling from the strati- 

 graphical point of view, but the disadvantage in this respect is much 

 more than compensated for by the evidence that it furnishes in favor 

 of the view that all of these beds really constitute one great series, 

 and as opposed to the view which it may l^e inferred that certain geolo- 

 gists hold that the series of these beds which I have included under 

 the name of Moencopie belongs to a different system and is in some 

 way connected with the /imderljdng Paleozoic rocks. This view, in the 

 light of the above-mentioned facts, is, in my opinion, quite untenable. 



THE LEROUX MEMBER. 



Under the name Leroux I include the remainder of the Shinarump, 

 deriving, the name from Leroux Wash," which enters the Colorado 

 Valley 2 miles below Holbrook, and on which, some 15 miles north of 

 HollDrook, this member attains the greatest development that I have 

 observed, probably reaching its maximum of 800 feet. These beds, 

 too, if studied at localities where they are less developed, might be sup- 



oThe name "Leroux's fork" was given to this wash by Lieutenant Wliipple's party, who followed it 

 down some distance and encamped at its junction with the Little Colorado on December 5, 1853, this being 

 their Camp 79. See Pacific Railroad Reports, Vol. Ill, Ft. I, p. 75. The name is written in two words on 

 the Land Office map of Arizona. 



