AN EOCENE FLORA FROM TRANS-PECOS TEXAS. 



9 



aries diverge at wider and wider angles and are more 

 curved in the upper half of the leaf until in the tip they 

 become very thin and diverge at angles of about 70°, 

 running straight about halfway to the margin, where they 

 turn abruptly upward to form wide arches to the adjacent 

 superiorsecondaries. Tertiary venation largely immersed, 

 consisting of transverse, slightly curved nervilles. 



Tliis species is one of the most distinctive 

 fossil species of Lauraceae known, and as it is 

 so much more abundant in the tuffs of the 

 Barilla Moxmtains than at the type locahties 

 the foregoing description may be somewhat 

 amplified, particularly as regards the limits of 

 variation and the areolation. Thus the small- 

 est leaves have a length of but 8 centimeters 

 and a maximum width of but 8 millimeters, 



while the maximum width of the largest speci- 

 mens is 2.25 centimeters. The areolation is 

 fine meshed and the nervilles, both those at 

 approximately right angles to the midrib and 

 those forming wide angles with them, appear 

 more promiaent, giving the areolation a decid- 

 edly quadrangular appearance, although in 

 reality the areolation is prevailingly polygonal. 

 The appearance of these leaves is well shown 

 m the accompanying illustrations, and they 

 distinctly corroborate the comparisons made 

 between the type and the existing Oreodaphne 

 guianensis Aublet, of northern South America. 

 In fact, but for the greater development of the 

 lower secondaries in the fossil, the two are 

 scarcely to be differentiated. 



