216 MESOZOIC FLORAS OF UNITED STATES. 



Elder Creek that Mr. Diller made his well-known section/ which so 

 staggered the geologists who are studying the age of the earth. Accord- 

 ing to this section the Knoxville beds have a thickness on Elder Creek 

 of 20,000 feet, the Horsetown beds of about 6,000 feet, and the Chico 

 beds of 4,000 feet, making 30,000 feet measured. And yet it seems that 

 "the complete series of the Shasta-Chico beds is not exposed in this 

 section."* The strata here often approach a vertical position and the 

 section stretches across theh upturned edges for a distance of nearh' 8 

 miles. They consist of shales, sandstones, and conglomerates with 

 calcareous bands in the Knoxville beds. There are no indications of 

 the existence of heavj' deposits of eruptive material or other forms of 

 rapid deposition, and the faulting and folding is slight and local. Doctor 

 Stanton, who has made later and more special examinations, thinks, 

 however, that certain facts observed by him may ultimately somewhat 

 modify these extreme results. There can be no doubt that these beds 

 embrace practicallj^ the whole of the Lower Cretaceous, and Doctor 

 Stanton would place the Chico beds in the Upper Cretaceous,with their 

 lower portion on about the horizon of the Cenomanian. 



These collections reached Washington in the autumn of 1895. I 

 made a preliminary study of them during the winter, comparing them 

 carefully with those previously received from substantially the same 

 localities. In many cases they proved much fuller and greatly increased 

 our knowledge of the flora of those beds, but in others, as alreadj^ stated, 

 Mr. Storrs and I were unable to find any additional material, and in still 

 others what we obtained was inferior in quantity and quality to that 

 previously collected. 



Professor Fontaine was at that time engaged on other work and 

 could not undertake the determination of these collections. I had 

 planned the series of papers now in progress and, as stated in the first 

 paper, deemed it important to begin with the lowest Mesozoic floras 

 and work up to those of the Lower Cretaceous. This plan has been 

 adhered to, although it necessitated the postponement of the determina- 

 tion of collections made earlier than some that have been published. 

 The histor}^ of this work has all been fully given in its proper place. 



"Am. Jour. Sci., 3d ser., Vol. XL, December, 1890, p. 476; Bull. Geol. See. America, Vol. V, 1894, pp. 

 439-440. 



b Bull. Geol. See. America, Vol. V, 1894, p. 438 (footnote). 



