DESCRIPTION OF SPECIES ADDED TO THE FLORA OF 



THE LARAMIE GROUP. 



FILICBS. 



Osmund a major, sp. nov. 



Plate XVIII, Fig. 5. 



Frond pinnate; pinnules simple, alternate, large and thick, linear-lanceolate, 

 unequilateral at base; borders undulate; medial nerve narrow; lateral nerves passing 

 to the borders at a broad angle of divergence, forking generally once from the base, 

 one of the branches sometimes forking again from the middle. 



This beautiful fragment seems to belong to the same species as that 

 of fig. 5, pi. iv, "U. S. Geol. Rep.." vii; at least the nervation is identical 

 in its characters. The borders of the leaflets, however, are very entire, 

 while they are obscurely crenulate in pi. iv, fig. 5. They come from the 

 same locality. On the other hand the fragments, figs. 6 and 7 of pi. iv, 

 vol. vii, have the same nervation as fig. 1 — that is, a very narrow midrib, 

 and the lateral veins forking more generally from the middle than from 

 the base. It is, therefore, uncertain whether these fragments represent 

 two or three species, or whether, perhaps, they may all be referable to the 

 same. 



Hub. — Golden. A. Lakes. Collection of Princeton College. 



Pteris erosa, Lesqx. 

 Plate XIX, Fig. 1. 

 "U. S. Geol. Rep.," vii. p. 53, pi. iv. fig. 8. 



Fronds simply pinnate; pinnae huge, linear-oblong, narrowed to a pointed acumen, 

 unequilateral at base; lateral nerves distant, obtusely diverging from the medial nerve, 

 curving down in joining it, forking at the base only, rarely one of the veins forking 

 again from the middle. 



By the shape of its leaflets and their nervation this species resembles 

 the former and should, perhaps, be identified with it. The borders are 

 sharply irregularly serrate, sometimes merely gnawed in places. 



Hah. — Same locality as the preceding; also communicated by Mr. Lakes. 

 It is the property of the Princeton College. 



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