VOL. X 



,3''] PROCEEDINGS OF THE NATIONAL MUSETJM. 263 



DESCRIPTION OF THE SPECIES. 



EQUISETACE^. 



Equisetum texense sp. uov. 



PI. XXXVI, Fig. 1. 



Stems small, 3 to 4 millimeters in diameter. Average length of inter- 

 nodes, 1 centimeter. Sheath swollen, average length, 5 millimeters. 

 Character of teeth not certainly made ont, but apparently they are 

 narrow and about twelve in number. This Equisetum is much like 

 E. Burchardti, Dunker, of the European Wealdeii, and resembles also 

 U. virginicumj of the Potomac formation, but it seems to have been 

 somewhat larger than the latter. It belongs to the type of Equiseta 

 with small stems and swollen sheaths that is characteristic of the Lower 

 Cretaceous. These three i»]ants, U. Burchardti., E. inrginictnn, and E. 

 texense, are all closely allied and are, i)erhaps, somewhat varying types 

 of the same species. 



Only one specimen was found that showed the sheatlis, and in this 

 case the preservation was not perfect enough to make fully known the 

 shape of the teeth. There are, however, several imprints which ap- 

 pear to have been made by portions of the stem of this ])lant. The 

 tumid character of the sheaths, however, is well displayed in the more 

 perfect specimen. The considerable length of this stem, its rigid na- 

 ture, and the appearance of the sheaths, remind one of Casuariua. 



FERNS, 



One of the most peculiar features of the flora collected at Glen 

 Eose is the almost total absence of ferns. Generally in any collection 

 of older Cretaceous fossils ferns are among the most abundant forms. As 

 these Texas fossils are preserved in sediment accumulated during a 

 progressing subsidence, we would expect them to show a large propor- 

 tion of ferns. This, however, i.s not the case. Only a single imprint, 

 with its reverse, was found belonging to this group, and this is the tip 

 of a pinna or pinnule, which is too small to permit the character of the 

 plant to be made out. 



Sphenopteris valdensis Heer ? 

 PI. XXXVI, Fig. 2. 



A small specimen was found of a tern of Wealden type, closely allied 

 to, if not identical with, »S'. valdeiiHis, described by Heer from the 

 Wealden of Portugal. The specimen is too small to ])ermit the posi- 

 tive determination of the plant. The fragment seems to belong to the 

 terminal portion of an ultimate pinna. As this portion of a fern often 

 differs much from parts lower down on the pinna, it is of no value to 



