FILICES. 151 



two do belong to one another. From the knowledge which we possess of 

 the leaf-stalks and stems of Botryopterideae, and which also we owe to 

 Renault, it seems tolerably certain that the group consisted of delicate 

 herbaceous Ferns. We shall have to return to them further on in order to 

 consider the anatomical details of their structure. 



The genera Rhacopteris and Noggerathia, the barren leaves of which 

 have already been discussed at some length, are both known also in the 

 fertile form. Stur is perhaps right in placing them in the family of Ophio- 

 glossaceae on account of their fructifications, but this relationship will not 

 be satisfactorily established for the botanist, until the remains have been 

 found as petrifactions and with their structure preserved. The only leaf 

 of Rhacopteris paniculifera 1 hitherto discovered has normal sterile pinnae 

 below; the main axis forks repeatedly at its upper end and forms a loose 

 tuft of small branches, the extremities of which are surrounded by crushed 

 and for the most part detached sporangia. These sporangia are small and 

 globular, and on one of them Stur believes that he has seen a fissure. He is 

 led to refer this fossil to Ophioglossaceae and to compare it with Botrychium 

 chiefly from the development of a fertile and a sterile portion of the lamina 

 in the same leaf, and because he could perceive no annulus on the crushed 

 sporangia. This reference therefore is obviously very precarious, for an 

 analogous behaviour is observed in the fertile leaves of very various Ferns, 

 and as regards the terminal position of the fertile leaf-segment there is no 

 really serviceable object of comparison to be found in Ophioglossaceae. A 

 similar state of things to that which occurs in Rhacopteris is also observed 

 according to Schimper 2 in Triphyllopteris Collumbi, Schpr., from the Culm 

 of Thann ; but here we have no certain ground to go upon owing to the 

 indifferent preservation of the specimen, and moreover it does not appear 

 from the text whether there is any proof of the connection between the 

 sterile and fertile portions figured, or whether this connection is concluded 

 merely from their occurring together in the strata. 



Essentially similar objections may also be raised respecting the genus 

 Noggerathia 3 . Its fructification, clearly ascertained from the circumstance 

 that the lowermost pinnate leaves are sometimes sterile and also show 

 the characteristic features of Noggerathia foliosa, was first described by 

 Geinitz 4 , and was declared to be of gymnospermous origin. Further light 

 was afterwards thrown on the question, and by no one more than by K. 

 Feistmantel 5 . The literature of the subject has been collected by Stur 6 . 

 By the close approximation of the pinnules to one another the fertile leaves 

 or leaf-segments assume the appearance of dense spikes ; the pinnae them- 

 selves change their form and become broad scales with the anterior margin 



1 Stur (4), p. 8, and (5), t. 8. 2 Zittel (1), p. 114. J Stur ^4) and ^5,. * Geinitz 



K. Feistmantel (1). Stur ^3,. 



