296 Systematic Paleontology 



Four species were recognized thus early, of which the exact occurrences 

 were not certainly known except in the case of Tempshya ScMmperi, which 

 came from the Wealden of England and Germany and which was described 

 by Stokes and Webb ^ in 1824 as Endogenites erosa. This was referred 

 to Sternberg's genus Protopteris by linger ^ in 1845. Similar remains 

 had previously been referred to Porosus by Cotta (1832) and also to 

 the genus Palmacites of Brongniart by Corda (1845-1846). 



Schenk^ in 1871 with material from the Lower Cretaceous showed that 

 Corda's view which had been based on fragments, that Tempshya repre- 

 sented the peripheral part of fern trunks with leaf bases and adveptive 

 roots, was not entirely accurate. From his more perfect material he 

 concluded that there were several steles of various sizes, the whole im- 

 bedded in parenchyma and probably enclosed in a cortex. According 

 to Schenk the smaller and more numerous steles consist of an axial 

 bundle of scalariform elements surrounded by a sheath of sclerenchyma, 

 while the larger show the fibrovascular elements arranged in a horseshoe- 

 like curve surrounding delicate parenchj'-matous elements. Subsequently 

 Hosius and von der Marck * described a species from the lower Senonian 

 of Westphalia and Velenovsky ° lumped a large number of occurrences 

 of WeaJden, Cenomanian, and Senonian forms under the new name 

 Tempshya varians. 



Schenk's smaller steles are now known to be adventitious roots of the 

 normal fern type, the central radial bundle being diarc according to 

 Seward but hexarc according to Solms-Laubach. The larger or true 

 steles are also typically filicinean and were compared by Schenk with those 

 of the Marattiacese. 



^ Stokes and Webb, Trans. Geol. Soc. Lond., 2d series, vol. i, 1824, p. 423, pi. 

 xlvi, figs. 1, 2; pi. xlvii, figs. 5a, b. 



^Unger, Synopsis Plantarum Fossilium, 1845, p. 107. 



^Schenk, Palseontographica, Band xix, 1871, p. 259, pi. xlii, fig. 4; pi. xliii 

 (separate p. 57, pi. xxi, fig. 4; pi. xxii). 



^ Hosius and v. d. Marck, Palseont., Band xxvi, 1880, p. 192, pi. xxxix, figs. 

 161-163. 



^Velenovsky, Fame bobm. Kreidef., 1888, p. 23, pi. v, fig. 5; pi. vi, figs. 1-7. 



