i66 STUDIES IN GEOLOGY, No. 4 



perhaps be justified in considering about 5,500 feet as an 

 average for the normal upper limit. 



The genus Heliconia contains between 30 and 40 existing 

 species which are confined to the American tropics, where 

 they range from the West Indies to Brazil, being especially 

 common in the rain forests of Central America and in the 

 montana region of the Eastern Andes from the Yungas of 

 Bolivia northward to the Caribbean. Fossil Musaceae have 

 been invariably referred to the genus Musaphyllum since 

 Gceppert proposed that name in 1854 for a fossil form from 

 the Tertiary of the Island of Java. Over a dozen fossil 

 species have been recorded, of which the majority are from 

 European localities. These appear to represent the genus 

 Musa, which appears to have invaded Europe from Central 

 and Eastern Africa during Oligocene times and continued 

 their existence on the former continent to the close of Mio- 

 cene times. 



Fossil forms that have been referred to Musaphyllum are 

 widely distributed in the present Rocky Mountain region of 

 North America in the earlier Eocene although none have as 

 yet been detected in the Tertiary deposits of the Atlantic or 

 Gulf Coastal Plain. I consider that these North American 

 forms probably represent the genus Heliconia, which in 

 addition to the present fossil species I have recently recorded 

 from the Miocene of Costa Rica. A third fossil species of 

 Heliconia is represented by the remains described by Engel- 

 hardt 12 from the Tertiary of the Rio Magdalena in Colombia 

 as Musaphyllum elegans. This form is also present in prob- 

 ably Miocene deposits at Betijoque, Venezuela, and repre- 

 sents a much larger and coarser species than the form under 

 discussion. 



12 Engelhardt, H., Abh. Senck. Naturf. Gesell., Bd. 19, p. 25, pi. 4, 

 figs. 1-3; pi. 5, fig. i, 1895. 



