180 STUDIES IN GEOLOGY, No. 4 



dividuals have been found growing in southern Trinidad. 

 The tree has never been recorded from Colombia, Central 

 America, or the Pacific Coast, but I collected characteristic 

 fruits in the sea drift of Panama Bay, so that this species 

 evidently grows somewhere in the Pacific water-shed of 

 Central or northern South America. 



Their presence in the latter region and the finding of this 

 well marked fossil species in the Pliocene of Bolivia suggests 

 an American origin for the family, and that the single west 

 African coastal species reached that region either by means 

 of the equatorial counter current, or before the continental 

 outlines had assumed their present form. As I have pointed 

 out on a former occasion, there are a number of distributional 

 facts which suggest that Guppy, in his admirable studies on 

 distribution, has underestimated the possibilities of this line 

 of travel. Although the main equatorial current might be 

 expected to carry coastal types from the Old to the New 

 World I see slight evidence of this having taken place, and 

 there is considerable evidence of dispersal in the opposite 

 direction. If the present Atlantic currents preclude effective 

 dispersal in the tropics from west to east, then we are forced 

 to assume that the late Tertiary oceanic circulation differed 

 from its present arrangement. 



The fruits of Sacco glottis tertiaria are present in the Pislly- 

 pampa deposits in considerable abundance and in a good state 

 of preservation. In so far as flieir reference to the Humi- 

 riaceae is concerned they are identified with absolute certainty 

 and they offer a striking contrast to the conditions that pre- 

 vail today on this bleak and treeless pampa, 11,800 feet 

 above sea level. 



Order THYMELEALES 



Family LAURACE/E 



Genus MESPILODAPHNE Nees 



Mespilodaphne boliviano Berry, sp. nov. 



PLATE VIII Fig. 3 



Leaves of large size, lanceolate in general outline, widest 

 in the middle and acutely pointed at both ends, with entire 



