﻿188 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 12, 



tended sense, as characterized by the fructification and not by the 

 veins. The generic character may be thus expressed : — 



Frond bipinnate. Leaflets with a midrib ; lateral veins oblique, 

 dichotomous. Fructification closely covering the whole, or an inde- 

 finite part, of the under side of the unchanged leaflets ; not forming 

 definite sort. 



I do not know of any other species referable to the genus ; for the 

 Sagenopteris Phillipsii, formerly placed in it by Goeppert, agrees 

 with the present species in no one character, except such as are 

 common to all Ferns. 



6. Pecopteris exilis, Phillips, Geol. Yorks. t. 8. f. 16. 

 Pl. XIII. fig. 5a, 5b. 



P. obtusifolia, L. & H. Foss. Fl. t. 158. 



Cyatheites obtusifolius, Goepp. Syst. Filic. Foss. p. 328. 



I have satisfied myself by the examination of authentic specimens, 

 that the Pecopteris obtusifolia of Lindley and Hutton is identical 

 with Mr. Phillips's P. exilis; and the latter, as the earlier name, 

 ought to be retained. P. acutifolia (Foss. Fl. t. 157), which differs 

 in nothing but the acute tips of its leaflets, can hardly be considered 

 as a distinct species. It is singular that both should be omitted in 

 M. Brongniart's catalogue of the fossil plants of the Oolite. Prof. 

 Goeppert placed them in his genus Cyatheites, remarking at the same 

 time that it was very possible their real affinity might rather be with 

 the Aspidia. In their general form they certainly have quite the 

 look of that genus ; but in one specimen that I have examined of 

 P. exilis, the appearance of the fructification is such as seems to in- 

 dicate an affinity with quite a different group of Ferns. The capsules 

 in this specimen appear not to form sori, but to be arranged singly 

 in a regular row on each side of the midrib : each capsule is of a 

 large size in proportion to the leaflet, of a figure between ovate and 

 spherical, and marked on the top with distinct and regular striae ra- 

 diating from a depressed central point. Their structure, in short, 

 appears extremely similar to what is seen in the recent Schizceacece, 

 especially in Anemia and Mohria ; the only difference, as far as I can 

 make out, is, that in all the recent Ferns of that tribe, the capsules 

 are crowded together on a part of the frond which is more or less 

 contracted and transformed ; whereas in our fossil, they are more 

 distantly placed on the unchanged leaflets. The only fossil Fern 

 hitherto described, in which such a structure of the capsules has been 

 observed, is the Senftenbergia elegans, so elaborately figured and de- 

 scribed by Oorda* : this is very like our Pecopteris exilis in the 

 form of its leaflets, and the position and general appearance of its 

 capsules ; but it has the terminal ring of those capsules composed of 

 several rows of radiating cells, whereas in our plant there appears to 

 be only one row of such cells, as is the case in all the recent kinds. 

 Corda's Senftenbergia is a fossil of the Coal-formation. 



* Beitrage, p. 91. tab. 57. f. 1-6. 



