396 PALEONTOLOGY 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. 



PL 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 rachis straight and flat ; medial 

 nerve thick and enlarging toward its slightly decurrent base, 

 with five pairs of alternate veins slightly curved upwards and 

 forking at the middle. 



o 



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. 



PL 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 rachis, 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 rachis, of its long nearly linear leaflets at- 

 tached to it by their whole base, especially of its obsolete nervation, the vein- 



