PLIOCENE PISLLYPAMPA BOLIVIA 169 



surface appearing as if villous in life. Length ranging from 

 2.5 cm. to 16 cm. Maximum width ranging from 1.9 cm. to 

 10 cm. These leaves are very common at Pisllypampa and 

 the usual size is about 13 cm. in length by 8.5 cm. in maxi- 

 mum width. The extremes of size as given above are con- 

 sidered as variants, or in the case of the very small forms as 

 juvenile or reduced leaves in proximity to floral organs. 

 Petiole stout, its length undeterminate, forming an angle 

 with the lamina. Midrib stout, prominent on the lower sur- 

 face of the leaf. A lateral primary diverges from the midrib 

 on either side at the extreme base at an angle of about 60 

 degrees, curving immediately upward and ascending rather 

 straightly to, or slightly above the middle of the leaf, where 

 it joins a lateral branch from the lowest secondary. Secon- 

 daries stout and prominent, 6 or 7 opposite to alternate pairs 

 diverge from the midrib at regular intervals, at angles of 

 about 50 to 55 degrees, curving upward, sub-parallel, abruptly 

 camptodrome close to the margins. There is a considerable 

 interval between the basal primaries and the lowermost sec- 

 ondaries. The lateral primaries send off on the outside at 

 regular intervals sub-parallel secondaries which are abruptly 

 camptodrome close to the margins. The basal secondaries 

 send off laterally near their tips, three or four similar campto- 

 drome tertiaries. The normal tertiaries, which are prominent 

 on the lower surface of the leaf, are at approximately right 

 angles to the veins which they connect; they are simple or 

 branched, at regular closely spaced intervals and are rather 

 straight except in the sinuses formed between the secondaries 

 and the midrib, where they are more curved ; they are con- 

 nected by thin, irregularly inosculating riervilles the vena- 

 tion as a whole being characteristic of this genus. 



I have figured several of the smaller leaves of this species. 

 These may be short and broad, or longer and narrower with- 

 out, however, departing from the general facies of the 

 species. 



