FOSSIL PLANTS OF JANCOCATA 213 



Order ROSALES 



Family ROSACES 



Genus OsTEOMELKS Lindley 



Ostcomeles koslowskiana Berry sp. nov. 



PLATE I Figs. 4, 43. 



Leaves of small size, obovate or broadly spatulate in gen- 

 eral outline, widest in the middle, broadly rounded at the 

 apex, and decurrent at the base to the short and stout petiole. 

 Marg-ins entire below, with a few crenate teeth apically. 

 Texture subcoriaceous. Length about 8 mm. Maximum 

 width about 6 mm. Lamina broader on one side than on the 

 other, and the base also somewhat inequilateral. Petiole 

 stout, about 1.5 mm. long. Midrib relatively very stout, 

 prominent on the under side of the leaf. Secondaries rela- 

 tively stout; about 5 pairs diverge from the midrib at angles 

 of about 45 degrees, pursue relatively straight, subparallel 

 courses and are abruptly camptodrome close to the margins. 

 Tertiaries percurrent. 



This characteristic little leaf is typical of the genus Osteo- 

 meles, or Hesperomeles as it is sometimes called. The genus 

 contains about a score of existing species the majority of 

 which are unarmed or spinescent shrubs of the Cordillera 

 region of South America where they range from Central 

 America southward to Bolivia. Among these the fossil ap- 

 pears to be most similar to Osteomeles intermedia Pittier 

 which was described recently 5 from the Cordillera de Santa 

 Marta in Colombia from an altitude of 8937 feet, and to 

 Osteomeles obovata Pittier from the Irazu volcano in Costa 

 Rica from an altitude of 9750 feet. Too little is, however, 

 known of the occurrence of the genus in the mountains of 

 Peru and Bolivia to attach any particular importance to this 

 similarity of the fossil species to these existing forms from 

 so much farther north. Osteomeles pcrncttyoides (Wed- 



3 Pittier, H., Cont. U. S. Natl. Herb., vol. 20, pt. 3, p. 107, 1918. 



