420 Systematic Paleontology 



The epidermis is made up of small rectangular thick walled cells 

 and is very coriaceous, as are apparently the cortical tissues, which serves 

 to account for the preservation of the twigs in such abundance where 

 the materials have been much macerated as at Plaster Bluff on the 

 Little Missouri Eiver, Arkansas. 



This genus was founded by Schenk upon abundant material from 

 the WernsdorferschicMen, with Thuites HoJieneggeri of Ettings, as the 

 type and only species. This was, he says, the most abundant fossil in 

 those beds in which it occurs, and it received a careful and elaborate 

 treatment at his hands. This species has subsequently been recognized 

 in the Kome beds of G-reenland, the Trinity of the Texas region, the 

 Earitan and Magothy formations of 'New Jersey and the Turonian of 

 Bagnols, France. In 1880 Hosius and van der Marck described a rather 

 illy-defined species, F. Konigii, from the Senonian of Westphalia^ and 

 the next year Heer ^ described an additional species, F. occidenialis from 

 Portugal which Saporta has shown ^ ranges from the TJrgonian of Cereal 

 through the Albian of Nazareth into the Cenomanian of Alcantara 

 and Padrao. The latter author also describes an additional species, F. 

 leptoclada * which is confined to the Lower Cretaceous of Portugal 

 (Neocomian-Aptian) . 



In 1889 Velenovsky described the Bohemian form F. hohemica from 

 the Cenomanian of that country (loc. cit.) and the next year Fontaine 

 described the two species from the Potomac Croup (loc. cit.) the same 

 author three years later founding a third species, F. varians upon material 

 from the Trinity Group of Texas.' Newberry in 1896 described the 

 ninth species F. gracilis ^ which is a very abundant type in the Earitan 

 and Magothy formations of the Coastal Plain and which has recently 

 been shown by Hollick and Jeffrey to be referable to a distinct genus. 



^ Palseont, vol. xxvi, 1880, pp. 132, 181, pi. xxxvii, fig. 148. 

 ' Cont. Foss. Fl. Port., 1881, p. 21, pi. xii, figs. 3b, 4-7. 



^Fl. Foss. Port., 1894, pp. 139, 199, 214, pi. xxvi, fig. 16; pi. xxxvi, figs. 1, 2; 

 pi. xxxviii, figs. 2, 3; pi. xxxix, fig. 20. 



*Loc cit, pp. 109, 113, pi. xix, fig. 18; pi. xxi, figs. 9-11. 



' Proc. U. S. Natl. Mus., vol. xvi, 1893, p. 273, pi. xl, figs. 1, 2; pi. xli, figs. l-3a. 



" Fl. Amboy Clays, 1896, p. 59, pi. xii, figs. l-3a. 



