404 
PALAEONTOLOGY OF ILLINOIS, 
Pecopteris dentata, Brgt. 
Veg. foss., p. 336, pi. 124. 
/ . 
C-. fyou y.z^ 
. @1ciyts/ ^4 . ^ 
A fine species found in large specimens in the shales of the coal at Morris,, 
and also in the concretions of Mazon creek. 
Pecopteris flayicans ? Presl. 
Svhenopteris flavicans? Presl. 7 1 • •- / , 2 >, 
6 * ,:'-V r . J 
Sternh., Vers., vol. II, p. 127. PI. xxxviii, fig. 1, a , b, c. 
From Mazon creek also, and in concretions, we have obtained a number of 
specimens of a species which appears closely related to this species, if it is not 
identical with it. They represent parts of fronds ©r pin rise, bipinnaiely divi¬ 
ded ) primary divisions alternate, open, straight or slightly flexuous, linear, 
bearing alternate, oblong, short, obtuse pinnules, connate at their base, slightly 
decurrent, with a decurrent medial nerve • alternately branching in simple 
veins, two or three on each side, turning inwards in ascending or straight to 
the border. The fruit dots are marked in a double row near the borders of 
the leaflets, apparently placed upon the veins. The main rachis and its divi¬ 
sions are deep and grooved. But for the position of the sovi and of the thick 
epidermis of its leaflets, this species could be referred to Oligocarpia Gutbieri, 
Gopp., the disposition of the deeply marked veins and the form of the pinnules 
being alike. As this Pecopteris flavicans is not mentioned by any recent au¬ 
thor, not even by Unger, and as it is known only by the short description and 
the incomplete figures given of it by Sternberg, our species is referred to it 
with doubt. 
Pecopteris chcerophylloides, Brgt. A 
It is remarked, vol. 2, p. 443 of this Report, that this species was still un¬ 
certain, having been found only in incomplete specimens. It has been ob¬ 
tained since from the roof shales at Colchester in large and good specimens. 
Except Pecopteris Cistii, Brgt., P. velutina, Lesqx., P. Neivberryi , Lesqx., all 
the species of Pecopteris enumerated in the 2d vol., have been since found in 
Illinois. 
