148 FILICES. 



with others of the kind, such as are found in the series of Marattiaceae. 

 Again, Stur unites the genus Dactylotheca l and also Pecopteris exigua 2 , 

 known only from the siliceous fragments of Grand' Croix, to Corda's genus, 

 while Zeiller :i protests warmly against this proceeding. In both certainly 

 the sporangia are isolated, as in Senftenbergia, but fresh researches may be 

 required to clear up their differences. Lastly, to come back once more to 

 the disputed question of placing our genus with Marattiaceae, it is clear 

 that we must extend the characters of this family considerably before we 

 can introduce into it forms with so highly developed an annulus as Renaultia 

 and Senftenbergia ; still this would be a wiser course, considering other 

 points of connection which exist between these Ferns and forms which un- 

 doubtedly belong to Marattiaceae, than to found new families upon them, 

 or to thrust them not without violence into others that are already estab- 

 lished. There may possibly be intermediate forms ready to our hand, 

 which would actually fill the gap between the exannulate Marattiaceae and 

 various annulate groups, and in that case we might think of Senftenbergia 

 in connection with Schizaeaceae and of Renaultia with Osmundaceae. For 

 we cannot with Stur so entirely put aside the resemblance between the 

 sporangium of Senftenbergia and that of Schizaeae, when Bunbury 4 also, 

 describing the fructification of Pecopteris exilis, Phill. from the Oolite of 

 Scarborough, says in reference to its likeness to Corda's Senftenbergia that 

 it is distinguished from it only by the circumstance that its apical annulus 

 consists of a single row of cells. We should thus have a genuine member 

 of the family of Schizaeaceae from deposits which are at any rate fairly old. 

 A re-examination of the original specimen would be very desirable. As 

 regards Stur's 5 genera Sphyropteris and Hapalopteris, of whose connection 

 with Senftenbergia I am not fully convinced from the author's statements, 

 it will be sufficient to refer the reader to the original publications. In con- 

 clusion, Sarcopteris Bertrandi 6 should be noticed here, a species known to 

 us only in a few transverse sections of fragments of fertile leaves from the 

 pebbles of Grand' Croix. The spherical thick-walled sporangia stand singly, 

 and not grouped in sori, on the lower surface of the very thick lamina, and 

 show on one side a large-celled irregularly defined tissue marking the position 

 of an annulus and reminding us of Stur's Renaultia. 



The Angiopterideae, which are characterised, as is well known, by free 

 sporangia uniting to form sori with a distinct configuration, are considered 

 by Stur to include only two forms, the remains of which were obtained by 

 Renault 7 from the pebbles of Grand' Croix and placed in the genus 

 Pecopteris. These species are named by Stur Grand' Eurya Renaulti and 



1 Zeiller (7), t. 9. * Renault (2), vol. iii, t. 19, ff. 13-18. * Zeiller (6). * Bunbury (1), 

 p. 188 ; t. 13, f. 5. s Stur (3) and (4). Renault (2), vol. iii, t. ai, ff. 12-15. T Renault 

 (2), t. 3, f. 19. 



