FOSSIL PLANTS. 395 



the upper part. They are scarcely lobed, and covered by groups of sporanges, 

 apparently confluent, and of undeterminable form. Prof. Geinitz figures and 

 describes them as star-like. 



ALETHOPTERIS CRISTATA, Gein. 



Verst., p. 29, PL 32, fig. 6. 



Pecopteris (Diplagites) cristatas, Gutb. 



We have only small fragments, which, by the size of the pinnae and by their 

 divisions, are referable to this species. As the nervation is obscure, it can- 

 not be positively seen whether they do not perhaps represent different parts of 

 a frond of the former species. The European specimens, at least so far as they 

 are figured, leave us in the same doubt about the value of the species. 



From the shales of the Morris coal. 



ALETHOPTERIS MURICATA, Gopp., Syst. 

 Pecopteris muricata, Brgt. 



Hist, veget. foss., p. 352, PL 9V. 



Good but small specimens of this species have been obtained in the concre- 

 tion of Mazon creek. It appears to be rare in the western coal fields. 



ALETHOPTERIS PLUCKNETI, Gein. 



Verst., p. 30, PL xxxiii, fig. 425. 



Nothing proves better than this species the insufficiency of our classification 

 of the fossil plants of the Coal Measures. First, a Felicites for Schlotheim, 

 it has been a Pecopteris for Brongniart, an Aspidites for Goppert, and now an 

 Alethopteris for Geinitz. The form of its pinnules, especially those of the lower 

 pinnae, seems to force its admission into this genus. Some good specimens 

 have been obtained from the shale of Morris, especially part of a tertiary pin- 

 nae, bearing large leaflets with a broad base, lanceolate pointed, scythe-shaped 

 in form, with the borders divided by alternate obtuse lobes, whose surface is 



