398 Berry: MESOZOIC FLORA OF ATLANTIC COASTAL PLAIN 
species is readily distinguishable from all of the foregoing and 
adds a well-marked and probably trifoliate Cretaceous form to this 
genus, which is so largely developed during Tertiary times. In 
the existing flora Rhus is a prominent element with upwards of 
150 species, which are for the most part natives of warm temperate 
and tropical regions. A modern species with almost identical 
foliage is Rhus villosa L., a south African form. 
OccURRENCE: Woodbine formation, Arthurs Bluff, Red River, 
Lamar County, Texas. 
CoLLection: U.S. National Museum. 
Zizyphus lamarensis sp. nov. 
DEscRIPTION: Leaves elliptical in outline, 4.5 cm. to 5 cm. i 
length by 3 cm. in maximum width about midway between the 
apex and the base, slightly nearer the latter; base full and rounded; 
lateral margins full and rounded; apex rounded, slightly less full 
than the base; margin with regular but shallow crenate teeth 
becoming less prominent toward the base. Midrib slender but 
prominent, straight. Lateral primaries one on each side, diverging 
from the midrib at its extreme base at an acute angle (about 10 ), 
two or three alternate thin pairs in the apical region, camptodromé; 
secondaries from the lateral primaries five or six in number, 
outside, curved, camptodrome; the lowest secondary 1s a 
and branches at the most acute angle (about 10°) and from thé 
extreme base, each successively ‘higher secondary subtending 4 
slightly larger angle and following a somewhat shorter pus 
Internal tertiaries more or less percurrent, marginal ones simula 
to the secondaries from the primaries in their arrangement @ 
course, thin and camptodrome. (PLATE 31, FIG. I.) 
This handsome species of an undoubted Zizyphus 18 BN - 
tunately represented by very scant material. It is entirely distim : 
from any described Cretaceous species and is much closer to variou 
Tertiary and still existing forms. It has recently been detect 
in the lower Tuscaloosa of Alabama. 
s is unfor- 
RHAMNALES 
RHAMNUS TENAX Lesquereux 
Rhamnus tenax Lesq. Am. Jour. Sci. 46: 101. 1868; 
Group 170. pl. 38. f. 6. 1892. 
Fl. Dakota 
