222 



LOWEE EOCENE ELOEAS OF SOETTHEASTEliM .\0UT11 AMERICA. 



The geologic liistoiy of Pniiiiis is as yet but 

 little undei-stood. About 70 fossil species 

 have beeu described and most of these are 

 based on leaf remahis, although the stones are 

 common in the German and other lignitic de- 

 posits. Upjier Ci-etaccous forms are known 

 from the Raritan and Dakota formations in 

 this country and from the Emscherian of Silesia, 

 and the Eocene records include Alaska and 

 Greenland. In later Tertiary time Prunus 

 grew on all the great land masses of the North- 

 ern Hemisphere and dming Miocene time its 

 range apparently was somewliat greater than 

 its present range. For exami>le the stones of 9 

 species are found in tlie Pliocene deposits of 

 Holland,' representing 1 European, 2 oriental, 

 and 2 entirely extinct species. 



iVmong previously described fossil forms 

 Prunus nahoiiensis seems most similar to 

 Prunus deperdita Heer, so elaborately described 

 by Laiu'ent - in his recent work on the flora of 

 the Sannoisian of Menat in the Auvergne. 



Occurrence. — About 3i miles southeast of 

 Naborton (NW. i NE. } sec. 19, T. 12 N., R. 11 

 W.), De Soto Parish, La. (collected by G. C. 

 Matson). 



Collection. — U. S. National Museum. 



Family MIMOSACE^;. 

 Section PHYLLODINE^. 

 Genus ACACIA Willdenow. 

 Acacia wiecoxensis Berry, n. sp. 



Plate LV, figures 1 and 2. 



Description. — Phyllode oblanccolate in gen- 

 eral outline, the apex broadly rounded, mucro- 

 nate pointed, and the base gradually narrowed 

 and pointed. Length about 5 centimeters. 

 Maximum width, in apical region, about 9.5 

 millimeters. Margins entire. Texture thin 

 and somewhat membranaceous or scarious. 

 Petiole short and stout, 1 to 2 millimeters in 

 length. Venation consists of a single fairly 

 stout midvein and a very fine lateral system, 

 scarcely visible without magnification, com- 

 posed of long and naiTow polygonal meshes, 

 the long axis parallel with the lateral margins. 



This species is based on the smgle specimen 

 figured on Plate LV, which in its size, outline, 



' Reid, Clement and E. M., The Pliocene (lonis of the Dutch-Prussian 

 border, pp. 101-103, pi. 9, flgs. 21-30, 101.5. 



* Laurent, liOui.s, Mus. hist. nat. Mar.seille Annales, Geologic, vol. 14, 

 pp. 152-100, pi. 13, figs. 9, 10, pi. 1-!, figs. 1-1, 6-10, 1912. 



apex, and venation is closely comparable with 

 the phyllodes of numerous existing species of 

 Acacia. The genus Acacia comprises about 

 4.50 tropical and subtropical species ui the 

 existing flora and these are largely confined to 

 Africa and Australia. The section Phyllodineaj, 

 with which Acacia wilcoxensis shows the closest 

 similarity, includes about 280 existing species 

 confinetl to Australia and Oceanica. Among 

 these are numerous forms suggestive of the 

 presenti species, as, for example, Acacia oblu- 

 nata Cavanilles, which is somewhat smaller, 

 and Acacia piycnantha Bentham, which is 

 somewhat larger than the fossil. Many other 

 similar existmg species might be enumerated if 

 it were worth wliile. Fossil species witli the 

 foliage reduced to phyllodes are not common. 

 Ettingshausen has described four such species, 

 Acacia coriacea,^ A. mimosoides* A. proser- 

 pinse.,^ and A. dianse,^ from the lower Oligocene 

 (Samioisian) of Haeiing in the Tyrol. The 

 last of these, though somewhat smaller, is 

 otherwise very similnr to Acacia wilcoxensis. 



Occurrence. — Holly Springs sand, ravine at 

 Oxford, Lafayette County, Aliss. (collected by 

 E.W. Berry). 



Collection. — U. S. National Museum. 



Genus INGA Willdenow. 

 Inga mississippiexsis Berry, n. sp. 

 Plate XLV. figure 1. 



Prunus caroliniana. Lesquereux (not Michaux), Am. 



Jour. Sci., 2d ser., vol. 27, p. 3G.3, 1859. 

 Lesquereux, in Safford, J. M., Geology of Tennessee, 



p. 427. pi. K, fig. (i, 1809. 

 Loughridge, Report on the geological and ceonomic 



features of the Jackson's purchase region, p. 196, 



fig. (i, 1888. 



Description. — Leaflets ovate-lanceolate in out- 

 line. Apex nan-owed and prolonged into 

 an acummate point. Base markedly mecjui- 

 lateral; outer side full and rounded; inner side 

 nearly straight and ascending, forming an 

 angle of 45° or less with the midrib. Length 

 about 5.5 to 6 centimeters. Maximum width 

 about 1.75 centimeters. Marguis entire, 

 straight and approximately parallel m the 

 median region of the leaflet, narrowing rather 

 suddenly distad. Petiolule veiy short and 



8 Ettingshausen, C. von. Die tertiiire Flora von Uaring in Tirol, p. 93, 

 pi. 29, tig. 47: pi. 30, figs. .01, 52, 1853. 

 *ldem, p. 93, pi. 30, figs. 00, 01. 

 s Idem, p. 94, pi. 30, figs. 53, 54. 

 'Idem, p. 94, pi. 30, figs. 58, 59. 



