210 Berry — An Eocene Ancestor of the Zapodilla. 



Eoachras eocenica gen. et sp. nov. 



Description. — Seed of large size, compressed laterally, 

 obliquely elliptical in outline when viewed from the side, 

 proximal end more broadly rounded than the distal end. 

 Length about 3'6 cm ; maximum height from dorsal to ventral 

 margin about 2*2 cm ; maximum thickness about L5 cm . The 

 seed has been subjected to pressure after burial by sediments 

 and this has destroyed the symmetry between the lateral 

 surfaces. Dorsal margin broadly rounded, sigmoid in outline 

 with a restricted but pronounced sinus toward the distal end. 

 Yentral margin thickened, considerably deformed, curved in 

 outlines : the umbilical sinus open, extending the whole length 

 of the seed. 



Occurrence. — Near Lexington, Holmes County, Mississippi. 



Discussion. — This seed differs from those of Achras zapote 

 in its slightly larger size, in its more open umbilicus which 

 also extends the whole length of the seed. As I have inter- 

 preted the orientation of the fossil, its smaller end is distal and 

 not proximal as in Achras, but this is a negligible feature. Seeds 

 of Achras are shown in figs. 4, 5. The seeds of Calocarpum 

 are, as a rule, much larger, fusiform and not compressed : the 

 umbilicus occupies the whole inner face and this feature as 

 shown in figs. 6, 7, 9 may be profitably compared with that of 

 the fossil. The seeds of Lucuma are also very similar to the 

 fossil as may be seen in fig. 10. A fact of interest in the 

 present connection is the presence in the Upper Eocene of 

 Texas (Wellborn Sandstone of Jackson age) of leaves that agree 

 exactly with those of the existing Calocarpum viride Pittier. 



It is not possible to suggest the character of the foliage in 

 Eoachras. Achras has a dense cover of smooth, thin-veined, 

 coriaceous, evergreen leaves. Calocarpum on the other hand 

 has very large, ovate-lanceolate, coarse, deciduous leaves. 

 There are a considerable number of leaf remains associated 

 with the seed of Eoachras but none of these can be definitely 

 correlated with the latter. There are none that are comparable 

 with those of Achras. There are fragments of large leaves, 

 tentatively referred to the genus Terminalia, that might 

 possibly represent Calocarpum-like leaves. 



Regarding the environment of Eoachras it may be said that 

 the Middle Eocene (Claiborne) flora of the Mississippi embay- 

 ment is a coastal tropical flora* embracing such types as 

 Thrinax, Coccolobis, Pisonia, Inga, Copaifera, /Sophora, 

 Eagara, Sapindus, Eeynosia, Sterculia, Cinnamomum, Nec- 

 tandra, Rhizophora, Myrcia, Conocarpus, etc. It will thus 



* Berry, E. W., An Eocene flora in Georgia and the indicated physical 

 conditions; Bot. Gaz., vol. 1, pp. 202-208, figs. 1, 2, 1910. 



Berry, E. W., Prof. Paper U. S. Geol. Surv., No. 84, pp. 129-163, 1914 



