DESCKIPTION OF SPECIES— PALM^. 107 



Phyllitns improbatus, Iiesqx^ 



riate XIV, Fig. 18. 



Ehizocaulon gracile, Lesqx., Annual Report, 1873, p. 39G. 



Branches slouder, irregularly forking ; leaves (?) oblong, recurved or oblique, narrowed to a very 

 sbort pedicel; nervation obsolete. 



Comparing originally some fragments of this plant, all still more incom- 

 plete than the one figured, with Rhizocaulon iwhjstachiuin. Sap., as figured in 

 Schimper's Pal. Vdg(it., pi. Ixxx, fig. 8, I found a kind of likeness in the form 

 of the spikelets, which, when crushed, as are some of Ihc upper part of the 

 figures, seem to represent a surface covered, like our plant, with a carbona- 

 ceous layer, marked in the middle by an indistinct depression like a midrib. 

 I had not then obtained the admirable work of Saporta, iStudes, where the 

 genus Rhizocaulon is not only described in detail, but where many fine spe- 

 cies are illustrated. From it I had to see the double error of my former 

 nomenclature and description, Rhizocaulon gracile being one of the species 

 described by Saporta, and this fragment of ours being without relation wliat- 

 ever to species of this genus. It is still uncertain if the branch figured here 

 bears leaves or spikelets rendered obsolete by compression. Some of the 

 so-called leaves have no trace of a midrib, and seem mere flakes of carbona- 

 ceous matter of an oval, oblong, obtuse shape, seemingly narrowed to a very 

 short pedicel, or sessile. The fragments should have been omitted, as of a 

 character too uncertain for description, and are mentioned here merely to 

 correct a double error of determination. 



Habitat. — Black Buttes, burned shale, above main coal. 



PRINCIPES. 



PALM^. 



Specimens of Palm leaves and fruits are very abundant in the Lower 

 Lignitic Measures of this continent, especially at Golden, the Raton Mount- 

 ains, and in Mississippi. The number of species which they represent is 

 large; but their characters, when taken from fragments of leaves, or from 

 the rays only, are rarely definite enough to authorize specific or even generic 

 separation. I have therefore described and figured only the types more posi- 

 tively characterized, either by their leaves or by their fruits. 



The Eocene species of Palms, as represented by specimens of the Lower 

 Lignitic Ibrniations, relate, as far as we know them until now, to lliree gen- 



