402 PALEONTOLOGY OF ILLINOIS. 



PECOPTERIS VILLOSA, Brgt., Veg. foss., p. 316. 



PL 104, fig. 3. 



This species is the most abundant of all in the concretions of Ma/on creek, 

 which show it in its multifarious forms. The nervation does not appear to 

 have been seen by European palaeontologists. Brougniart does not give any 

 details of it, and Geinitz indicates it as simple, or with veinlets forking once 

 only, which is totally at variance with its true nature. The concretions con- 

 tain numerous parts of the plant preserved in a state of partial maceration, 

 either with pinme whose substance is destroyed, and which have nothing left 

 but the outlines of their leaflets, and the entirely free veins and veinlets ; or 

 pinna? half preserved, one part of which bears leaflets with the villous epider- 

 mis, while the other part has the veins and veinlets free of epidermis, and 

 quite distinct. From the form of its pinnule, the multiple divisions of its 

 pinnae, and of its veins, this Pecopteris is exactly similar to P. polymorpha, 

 Brgt., the veinlets dividing once or twice or more, according to the place and 

 size of the pinnules. 



i 



PECOPTERIS ARGUTA, Brgt. (fruiting.) 







PL xiii, fig. 12 and 13. 



The part of a pinna, as represented in the figure, bears leaflets, connate at 

 the base, oblong, lanceolate obtuse, somewhat shorter, more pointed, and more 

 distinct than is generally the case in sterile pinnae of this species. But as the 

 nervation, as well as the crenulate-toothed borders of the leaflets, are similar to 

 those of Pecopteris arf/uta, and as these peculiar characters are not known in 

 any other species of the coal. I consider this specimen as representing its fruit- 

 ing part, which was before unknown. The sort appear like inflated dots placed 

 just at the point of the simple veins or rather like conical sori, with the point 

 to the inside of the leaflets and the enlarged opening outside at the point of 

 the teeth, as marked, fig. 13, enlarged. Their form is distinct ; with a strong 

 glass they even appear filled with a pulverulent matter. According to the form 

 and the position of these fruit-dots, the species resembles an Aspidium, and 

 should be placed in the genus Aspidites, Gopp. Sterile pinnae of this species 

 are not rare in the shales at Morris. 



