-I.LKTIN A. M. N. H. 



Vol. XXXVI, Plate XXI. 



Rio Nki.jro fko.m ^I oxtioredo.n'dcj 



Upper limits of arborescent vegetation in tlie Rio Negro Valley; 



Bogota-Villavivencio Trail at the riglit. 



(Tropical Zone; Orinocan Fauna.) 



J u N T 



D R o Nh. I 



ear C 



Iqueza. Bogota-Villavicencio Trail leaves the floor of tlic \allej' at the right. 

 (Fusion of Temperate, Subtropical, and Tropical Zones.) 



