434 PALEONTOLOGY OF ILLINOIS. 



basilar prolongation into an ear-like appendage, and also tbe 

 thinness and ramification of the slightly arched and dichoto- 

 mous veins, are the same. But in Mr. Bunbury's species the 

 leaflets have all the same obovate, obtuse or oblanceolate form 

 and are opposite, while in ours these leaflets vary from short, 

 kidney-shaped, very obtuse, to oblong, lanceolate, acute in out- 

 line, and are alternate. The figure of the Nova Scotia species 

 also shows, perhaps by mistake, the veins running into or de- 

 current upon the main rachis, while in ours they evidently 

 come out from the base of the leaflets. Nevertheless these dif- 

 ferences are not marked enough to authorize a specific separa- 

 tion, and we may consider this branch of ours as the inferior 

 part, while Mr. Bunbury's specimen represents an upper part 

 of a frond. By the general outline and the apparent variations 

 of the leaflets, this species is related to the former; but it 

 greatly differs by the thinner, closer and arched veins. Lo- 

 cality: Mazon creek, Grundy county, Illinois. Coal No. 3. 



Odontopteris cequalis, Sp. nov. PI. 36, fig. 2. Nothing is 

 preserved of this peculiar species but the broken part figured 

 here. From this it is not possible to know anything about the 

 primary division of this fossil fern. By its peculiar nervation, 

 and the regularity of the obtuse pinnae, this species is different 

 from any other of this genus. The pinna was apparently 

 long and linear ; its leaflets, separated to below the middle by 

 an acute sinus, either slightly decurrent or perpendicular on 

 the narrow, convex, smooth rachis, are short, about of equal 

 size, rounded at the top ; the veins, though thin, are distinct, 

 distant, all parallel at and near the base, oblique or perpendicu- 

 lar, following the direction of the leaflets, and simple or fork- 

 ing once only from above the middle. The thinness of the 

 veins and the general form of the smooth, convex leaflets, sepa- 

 rate this species from Odontopteris Schloihemi, Brgt. Locality 

 and position : same as last. 



