8 PROCEEDIlSrGS OF THE N'ATION'AL, MUSEUM vol.75 



tropical American forms of various Sterculiaceae, Triumfetta (Tilia- 

 ceae) and Ulmaceae. There is considerable resemblance to certain 

 species of Momisia in the last family, but the equilateral cordate base 

 favors its reference to Gouiana in which a number of species, both in 

 the new and old worlds, are very similar. 



The fossil material comes from the older travertine at Leiva, 

 Department of Boyaca. 



The genus contains about two score species of herbs and climbing 

 shrubs found in all the Tropics and occasionally in the sub-Tropics. 

 Over half of the existing species are confined to northern South 

 America. Several Tertiary species have also been described from 

 the latter region. 



Order MAL VALES 



Family STERCULIACEAE 



Genus THEOBROMA Linnaeus 



THEOBROMA FOSSILIUM, new species 



Plate 1, Figures 13, 14 



This is based upon a single specimen, which shows in natural 

 section a nearly complete transverse and part of a tangential section 

 of the fruit. The axis and thick walls as well as the seed coats have 

 been replaced by calcium carbonate and the matrix and interstices 

 between the seeds consist of a dark calcareous mudstone. The whole 

 fruit is about 5 centimeters in diameter and oval instead of circular 

 in cross section because of the abortion of the ovules in three of the 

 cavities. The wall is ligneous and about 6 millimeters in thickness, 

 with a rough surface, but not appreciably ribbed or tuberculated. 

 There are five cells, but seeds are matured in but two of these. The 

 matured seeds are large and are oriented either horizontally or 

 obliquely, and more or less radially to the axis. They are rounded 

 at both ends and elliptical in cross section, the maximum equatorial 

 diameter being about 10 millimeters and the minimum about 8 mil- 

 limeters. The length is about 2 centimeters. The outer seed coat 

 appears to have been smooth and is about 1 millimeter in thickness. 

 The inner seed coat is prominently longitudinally striated. 



The specimen is unfortunately incomplete. It was collected by 

 Dr. Maurice A. Rollot at a locality called El Infierno, near Leiva, in 

 the Department of Boyaca. 



The geological age of the specimen is very uncertain. The country 

 rock around the Leiva Valley is Cretaceous Umestone (Hettner's 

 Villeta beds) overlain by his Guaduas beds, here supposed to be of 

 lacustrine origin. ^ There are thermal springs near Leiva and travertine 

 deposits, both ancient and modern. I have plants from both, but 

 the Uthology of the TJieohroma matrix differs from both of these and 



