SELLARDS.| Fossil Plants, Upper Paleozoic, Kansas. 405 
seen to pass as a thin line almost to the apex. The base as 
seen on one of the pinnules is deeply cordate, attached by a 
strong short pedicel, the lower side of the base being enlarged 
and extending downward. The pinnules are subopposite, fal- 
cate or nearly straight, and are gradually narrowed to the 
pointed apex. The rachis to which the pinnules are attached 
is finely striate. 7 
Formation and locality: Cherokee shales, Lansing, Kan. 
Neuropteris vermicularis Lx. Pl. XLVIII, figs. 2, 3; pl. LVI, fig. 8. 
Geol. Rept. of Kentucky, vol. 4, p. 434, 1861; Geol. Rept. of Illinois, 
vol. 2, p. 428, 1866; ibid., vol. 4, p. 385, pl. 6, figs. 1-8, 1870; 
Schimper, Paleont. Veget., vol. 3, p. 474, 1869. 
Pinne broadly linear or narrowly triangular, sloping from 
the base or a little above the base to an obtuse apex. Pinnules 
large, at right angles or inclined a little, alternate or sub- 
opposite, close or a little distant, usually very crowded, dense 
and overlapping, oblong, sides nearly parallel, apex obtusely 
rounded, base truncate, attached by the midvein, rounded a 
little above the base, the lower corners projecting downward, 
1 to 4 or more cm. long, reduced toward the top, the last one 
partly connate with the broadly spatulate, lightly lobed ter- 
minal pinnule. Veins numerous but clear and distinct, mid- 
vein continuing to somewhat above the middle, lateral veins 
distant near the center of the pinnule, where they leave the 
midrib obliquely and curve gradually to the border, dichoto- 
mizing in the smaller pinnules two, three, or four times and 
counting 22 to 26 per centimeter, in the larger pinnules fork- 
ing four to six times and counting 34 to 42 per centimeter. 
Lamina clear, the veins appearing as fine round threads. 
The pinnules of this species present, as compared with most 
other ferns, an unusual range of variation in the number of 
veins per centimeter. The veins counted at the border be- 
come more numerous as the pinnule increases in size. In the 
small lateral pinnules having veins dichotomizing only two or 
three times the veins count at the border not more than 22 to 
26 per centimeter. In the large pinnules, in which the divi- 
sions dichotomize four to six times the veins count 34 to 42 
per centimeter, becoming in the largest pinnules as many as 
A4 per centimeter. Near the midrib the veins are distantly 
separated, becoming close at the border by numerous dichot- 
omies, the number of dichotomies depending on the size of 
