62 PTEROID FERNS [CH. xxxviil 



of Paesia be held as such, then there is progression from typical solenostely 

 with undivided leaf-trace to higher states of disintegration seen in passing 

 along the series. Looking back to the source from which this whole sequence 

 probably sprang, there can hardly be any two opinions. The series of 

 Pteroid Ferns are Dennstaedtioid derivatives, and they lead that phyletic 

 sequence on to the common goal of the Acrostichoid state. 



In conclusion a brief reference may be made to the other genera grouped 

 by Diels under his Pterideae-Pteridinae, which have not been included in 

 the above list. Of these Cassebeera Kaulfuss is probably a specialised Cheilan- 

 thoid; Actiniopteris Link must be held in doubt as a "genus incertae sedis." 

 The reference of the other three genera — viz. Aviphiblestria Presl, Anoptej-is 

 Prantl, and Ochropteris J. Sm.ith — to a Pteroid affinity must also be left in 

 suspense, pending further enquiry. But such uncertainty, regarding any or 

 all of these, leaves unimpaired the argument based on the comparison of 

 those Ferns which clearly find their place in the Pteroid series. 



BIBLIOGRAPHY FOR CHAPTER XXXVIII 



609. Mettenius. Filices Horti Lipsiensis. 1856. 



610. Mettenius. Farngattungen, iii. Frankfurt. 1858. 



611. Hooker. Species Filicum, ii, p. 154. 1858. 



612. Hooker. Synopsis Filicum, p. 153. 1873. 



613. BuRCK. Indusium der Varens. Haarlem. 1874. 



614. LUERSSEN. Rab. Krypt. Flora, ill, p. 100. 1889. 



615. Prantl. Arb. K. Bot. Gart. pp. 16-18. Breslau. 1892. 



616. Christ. Farnkrauter d. Erde, p. 161. 1897. 



617. DiELS. E. & P. Natiirl. Pflanzenfam. I, 4, p. 254. 1902. 



618. Tansley & LULHAM. New Phyt. III. 1904. 



619. Thomas. yi(:;-t'J•//<:/^^^;;^ «/^r^?^w, New Phyt. IV, p. 175. 1905. 



620. Tansley. Filicinean Vase. Syst., New Phyt. Reprint, No. 2. 1908 



621. Hannig. Flora, p. 338. 1911. 



622. Schumann. Flora, Bd. 108, p. 201. 191 5. 



623. Von Goebel. Organographie, 11, p. 1137, etc. 1918. 



624. Bower. Studies VII, Ann. of Bot. xxxii, p. i. 1918. 



