396 
PALAEONTOLOGY OF ILLINOIS. 
generally convex and polished. This form is the same as that published by 
Geinitz, being in all its parts larger than the common one generally found in 
the eastern Coal Measures. 
Alethopteris spinulosa, Sp. nov. 
PI. xi, fig. 1 and 2. 
Frond broad, bi-pinnate; primary pinnae apparently long 
linear slightly tapering toward the point, divided into alter¬ 
nate broad, half an inch long, oval leaflets, joined above the 
base, cut at the obtuse top in sharp spiniform short teeth, 
separated by obtuse sinuses ; main stem round, regularly and 
narrowly striate ; secondary racliis straight and flatmedial 
nerve thick and enlarging toward its slightly decurrent base, 
with five pairs of alternate veins slightly curved upwards ah'd 
forking at the middle. 
This fine species has no relation, even distant, with any other published as 
yet from the Coal Measures. The veins and veinlets are not deep, but very 
distinct by their black color, as seen in fig. 2, enlarged. 
From the roof shales of the main coal at St. John’s, Perry Co. 
Alethopteris falcata, Sp. nov. . 
PI. xi, fig. 3 and 4. 
The specimen figured represents a part of a simply pinnate 
frond, or of a pinna with simple leaflets attached to a main 
broad smooth racliis, by their whole unconnected base. These 
pinnules, about two inches long, are linear-lanceolate obtusely 
pointed, scythe-shaped and entire. The veinlets perpendicu¬ 
lar to the half round medial nerve, are very close to each 
other, very thin, either simple or forked from the base. 
On account of its broad curved racliis, of its long nearly linear leaflets at¬ 
tached to it by their whole base, especially of its obsolete nervation, the vein- 
