MESOZOIC TIME — CRETACEOUS. 831 



eastward, overlapping toward the Cretaceous shore, beyond the Knoxville and Horsetown 

 beds, which form the lower part of the Shasta-Chico series. The Chico thus comes in un- 

 conformable contact with the Jura-Trias and Carboniferous and extends inland from the 

 Lower Cretaceous, as indicated upon the map, to the dotted line. The subsidence and 

 consequent transgression of the sea that gave rise to the landward overlapping of the 

 later beds of the Shasta-Chico series began soon after the great upheaval at the close of the 

 Jurassic, and continued to at least the middle of the Upper Cretaceous (Diller). 



In the Tertiary the Tejon beds of California are conformable with the Chico, and they 

 were regarded by Gabb, and also by White, as faunally continuous. The Tejon is absent 

 in northern California, and in Oregon it rests unconformably upon the Shasta-Chico series. 

 (Diller, 1893.) 



In Washington, the Puget group of White, underlying the Tejon, is a non-marine 

 formation containing beds of coal. It extends from near the Columbia to the Puget Sound 

 region, and is several thousand feet in thickness. From its MoUuscan and Plant remains 

 it has been supposed by Newberry and White to represent a part of the Laramie or Tejon 

 group. Baculites Chicoensis shows the presence of Chico beds on the Snoqualmie and 

 other rivers at the western foot of the Cascade Range. The same beds are found at Lucia 

 Island, just north of Puget Sound, and connect with the coal-bearing Nanaimo beds of 

 Dawson upon the eastern side of Vancouver Island. Their correlation with the Chico of 

 California is well established by fossils. (Diller.) 



In Vancouver and Queen Charlotte Islands, over the Lower Cretaceous, there are 

 (1) the Middle Cretaceous, consisting of sandstones, shales, and conglomerates (which are 

 9700' thick in the latter), and (2) Upper, consisting of shales and sandstones (1500' thick 

 in the latter). G. M. Dawson (1886). 



In Greenland, the plant beds of the vicinity of Disco Island, described by Heer, above 

 the Frome group, or Lower Cretaceous, consist of (1) the Atane group of the Middle 

 Cretaceous, corresponding nearly to the Colorado group, and (2) the Fatoot group of the 

 Upper, corresponding nearly to the Montana group. 



LIFE. 



1. Lower Cretaceous. 



Plants. — The beds have afforded the earliest remains of the modern 

 group of Angiosperms. They are associated with many species of Cycads, 

 and the flora has therefore a transitional character between that of the Jurassic 

 and the Upper Cretaceous. Remains of more than 300 species have been 

 described by Fontaine from the Potomac formation (U. S. G. S., 4to, 1889). 

 Among them are 75 Angiosperms, 22 Cycads, over 90 Conifers, and 140 

 Ferns. In 1894, 30 Cycad trunks were found in Maryland. 



Some of them occur in the Wealden (or Neocomian) of England, as 

 Pecopteris Browniana, Aspidiam Dunkeri, Sphenopteris MantelU (Fig. 1353), 

 and two Conifers of the genus Sphenolepidium. Four of the nine species of 

 Sequoia or Eedwood (the genus to which the giant trees of California belong) 

 agree with species described by Heer from the older Greenland Cretaceous. 

 The Cycad trunks of Maryland are of the species Cycadeoidea Marylandica 

 {Tysonia M. of Fontaine). No species is identical with any of those from 

 Triassic beds. The Angiosperms include species of Ficus (Fig. 1351) or 

 Ficophyllum, Sassafras, Aralia, Myrica, Platanus (or Plane tree), etc. ; and 

 several of the genera, as those of Ficophyllum, Protoeiphylhtm, have com pre- 



