214 STUDIES IN GEOLOGY, No. 4 



dell) Decaisne appears to be the commonest known species 

 in Peru and Bolivia. It has larger and pointed leaves, and 

 reaches altitudes of between 11,000 and 12,000 feet in the 

 Cordillera Real of Bolivia. 



A second fossil species, not far removed from the Janco- 

 cata form is not uncommon in the Pliocene deposits at Coro- 

 coro and Potosi, Bolivia. It is closer to the existing Osteo- 

 meles cuneata (Lindley) Decaisne of this same region than 

 is Osteotneles kozlowskiana. The latter is named in honor 

 of .Senor Roman Kozlowski, who has done so much to ad- 

 vance our knowledge of the geology of Bolivia. 



Genus POLYLEPIS Ruiz & Pavon 



Polylepis tomentella folia Berry sp. nov. 



PLATE I Figs, i, ia 



Although I do not have the entire leaves, the great similar- 

 ity of the fossil to the leaflets of the existing Polylepis race- 

 mosa Ruiz & Pavon leads me to regard the present speci- 

 men as representing a detached leaflet of a fossil form that 

 is related to this common Andean tree of the present day. It 

 may be characterized as follows : Leaflets small, sessile, ovate 

 or narrowly elliptical in outline, widest medianly, with a 

 rounded tip and a cuneate base. Margins entire below, 

 prominently crenate above. Texture subcoriaceous. Length 

 about 14 mm. Maximum width about 6 mm. The species 

 is based upon the single known specimen which is figured on 

 the accompanying plate and this may well represent the 

 minimum rather than the average size. Midrib stout, prom- 

 inent on the under side of the leaflet. Secondaries well 

 marked, about six pairs, diverging from the midrib at acute 

 angles, and camptodrome. Nervilles percurrent. 



This well marked little leaflet is similar to those of the 

 existing Polylepis racemosa Ruiz & Pavon, a rosaceous tree 

 that is very characteristic of the Western Andes in southern 

 Peru up to elevations of 14,625 feet. I do not recall seeing 



