40 UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



top, where they are cut in two or three irregular, short, pointed or obtuse 

 lobes. The main stem and the divisions have in the middle an inflated large 

 nerve, more or less distinct, but traceable in the whole length and forking 

 with the branches, at a distance below the sinuses ; the substance of the 

 plant appears membranaceous or subcoriaceous, somewhat thick, as seen 

 upon the borders, which, here and there, are slightly raised above the stone in 

 their undulations. 



The nearest relation of this species among the fossil plants is Delesse- 

 rites sphferococcoides, Ett., Eoc. Fl. des Monte Prom., p. 8, pi. i, fig. 1. The 

 affinity is still more distinctly marked with some species of the present marine 

 flora, D. alata, D. sinuosa, etc., but especially with the fine Botryoglossuin 

 platicarpum, Kutz, of California. Indeed, the coriaceous or cartilaginous sub- 

 stance of this species rather refers it to this last genus than to the delicate 

 membranaceous fronds of Delesseria. 



Of the eight fossil species of this last genus described by European 

 authors, seven belong to the Eocene, or the Lower Tertiary, four being from 

 Mount Bolca and from Radoboy, and two from Mount Promina. The other 

 species described by Sternberg as an Haliserites, H. Reichii, and considered 

 by Schimper as a Delesseria, is from the Upper Cretaceous of Niedershoena in 

 Saxony. 



Habitat. — On upraised white sandstone rocks under or between the coal- 

 beds of Golden, Colorado. 



CAULERPITES, Schp. 



Canlerpites incrassatus, Lesqz. 



Plate I, Figs. 11, 12. 



Delesseria incrassata, Leeqx., Annual Report, 1872, p. 374. 



Frond siraple (?); lamiute either trifid from the base or simple, sessile, close, obovate, narrowed 

 downward ; surface rugose. 



The specimen seems to represent the upper part of a frond by three 

 divisions, or laminae, apparently joined at their base to a common axis. These 

 segments, deeply impressed into the stone, are either rounded or slightly 

 cuspidate at the top, gradually narrowed toward the base, as seen in fig. 12. 

 From irregular, half-round scars, represented upon an indistinct continuation 

 of the axis, fig. 11, it seems as if the laminae had been sessile, half embracing ; 

 but the specimen does not show precisely any trace of divisions between the 

 segments, and it is therefore uncertain if they were separated or connected at 

 the base, opening altogether at the upper point of the axis as verticillatc, or 



