118 U^'1TED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



species is doubtful, it is advisable to use different names in consideration of 



suggestive modifications of characters by influence of geographical distribution. 



Habitat. — Raton Mountains, near Fischer's Peak {Dr. F. V. Hnydcn). 



Gconomites Ungeri, sp. nov. 



Plate XI, Fig. 8. 



Frond large, flabellate or flabollato-piniiate(?) ; r.ays numerous, undivided, half-round, narrow, 

 joining \>y tbeir wholo base a broad, nerved rachis. 



The fragment is comparatively small, but some of the characters of 

 the leaf which it represents are clearly defined. The frond was a very large 

 one, as seen from its broad rachis, which, though broken in its length, is still 

 two centimeters at its base, apparently gradually decreasing upward, and 

 distinctly striate, at least toward the base, where it is somewhat concave. 

 The leaf accordingly seems to have been broadly linear-lanceolate. The 

 numerous narrow, inflated rays join the rachis by their whole base, neither 

 narrowing nor decurring to it, passing up in an acute angle of divergence, 

 25° to 30°, and slightly curving inward. They are nearly linear, five milli- 

 meters at the base, flat underneath, as seen in the upper part of the specimen, 

 which is merely a counterpart of the underside of the rays, and here marked 

 by nerves about two millimeters distant, with four or five thin intermediate 

 veinlets. The veinlets upon the petiole are of the same kind, but without 

 primary nerves. 



As far as can be seen, this species is distantly related to Manicaria 

 formosa, Heer (Fl. Tert. Helvet., i, p. 92, pi. xviii), where is figured a 

 splendid specimen, whose rachis is, however, totally destroyed. From the 

 distance of the rays at the base, this rachis seems to have been broad. 

 The relation is especially in the size, the inside curve, and the nervation of 

 the rays, which, however, in our specimen, join the rachis at a more acute 

 angle of divergence than in Heer's species, are half-round above, the line of 

 separation being marked by a deep groove. In considering the generic rela- 

 tion of his species. Prof Pleer remarks that it is not referable to Geonoma, 

 whose fronds have a narrow rachis, with rays in an acute angle of divergence. 

 This American species therefore would be related to Manicaria by its broad 

 rachis only, but differ from it by the more acute angle of direction of its half- 

 cylindrical rays, which relates it to Geonoma. 



Habitat. — Raton Mountains, New Mexico {Dr. F. V. Hayden). The 

 same specimen bears the leaf described as Ficus Smithsoniana. 



