388 PALEONTOLOGY OF ILLINOIS. 



of this kind on the veinlets of Neuropteris eorafata, Brgt., and which is also 

 often remarked on specimens of our N~. hirsuta, has been considered by Euro- 

 pean authors as representing organs of fructification. As the form and thick- 

 ness of the inflation is very irregular, it may be caused on both species by some 

 casual influence in the process of mineralization. The basilar leaflets of this 

 species show a tendency to be divided into lobes and pinnules, having thus the 

 same form as some of those of Neuroptcris Desorii, Lesqx., to which this spe- 

 cies is related, and from which it differs only by the thick epidermis, and by 

 the more distant ramification of the veinlets. The small fragment mentioned 

 in vol. ii of this Keport, p. 430, as possibly belonging to N. Desorii, Lesqx., 

 is referable to this species. 



GENUS DICTYOPTERIS, Gutbier. 



Aldr. u Verst., p. 62. 



FROND at least tripinnate, pinnae linear-lanceolate, bearing 

 alternate leaflets much variable in size, ovate-oblong obtuse 

 squarely cut at the base, with equal lobes on both sides, or 

 with the lower lobes slightly elongated. Medial nerve none, 

 or merely basilar ; veinlets anastomosing from the base, arched 

 towards the borders, but irregularly undulating in ascending, 

 and forming by their contact an oval-polygonal reticulation. 



DlCTYOPTERIS RUBELLA, Sp. nOV. 



PI. vii, fig. 2 to 6. 



FROND bi or tripinnate ; pinnae linear-lanceolate, with alter- 

 nate oblong or oval-lanceolate leaflets, attached to the rachis 

 by a broad pedicel. The inferior basilar lobes, as is generally 

 the case in the species of the genus Neuropteris, are slightly 

 longer or protracted into a little obtuse auricle. The terminal 

 leaflet, somewhat broader and longer, is oval in outline, ob- 

 tuse, and cut on one side into a short obtuse lobe, fig. 2. The 

 leaflets of the large inferior pinnae are more distant, larger, 

 truncate at the base, slightly scythe-shaped outwards; and 



