• J. SMITH ON THE GENERA OF FERNS, 175 



son oblong, protruding through dense elongated scales ; in- 

 dusium obsolete. — Fronds 2 to S inches long, linear, sinuous, 

 pinnatijid, or pinnate, coriaceous, the under side densely covered 

 with elongated fringed scales; veins digitately branched, the 

 branches anastomosing, the lower exterior one sporangiferous 

 on the side facing the primary midrib of the frond. 



Species. 1. C. officinarum, Willd. ( Asplenium Ceterach, Linn. 

 Grammitis Ceterach, Sw. Scolopendrium Ceterach, Swi.) 2. 

 C. cordata, (Acrostichum, iiwn. .Grammitis, Sw. Notholsena, 

 Desv. Gjmnogramma, Spreng. Ceterach crenata, Kaulf.) 



Illust. Sckk. crypt, t. 7. b. Hook, et Grev. Jc. Fil. t. 156. 

 Newman's Brit. Ferns, p. 85. 



Obs. The synonyms given to the two species of this genus 

 will show the several opinions of authors as regards their aflB- 

 nity and their value, viewed as a distinct genus; but in my 

 opinion, the unilateral sporangia clearly point out their re- 

 lationship to be with Asplenium rather than with any genus 

 near Grammitis; the absence of the indusium being, accord- 

 ing to my view, entirely owing to its being suppressed by the 

 density of the scales, which particularly characterize these two 

 species, and which is* analogous to the Lepicystis section of 

 Goniophlebium in Polypodiece. In Ceterach officinarum the 

 venules are combined, a character not before noticed. I 

 have not yet had sufficient evidence to say whether or not a 

 like structure characterizes C. cordata; but however unsatis- 

 factory the generic character of Ceterach may be, yet it ap* 

 pears to me on viewing every point of structure, that enough 

 is known to warrant their separation from any of the genera 

 in which they have hitherto respectively stood. By Presl 

 retaining it in Gymnogramma, he shows that he had not 

 examined the venation with that attention which the subject 



requires. 



71. Neottopteris, J. Sm. 



(Asplenii sp. Linn, and authors.) 



Feins forked; venules direct, parallel, sporangiferous on 



their superior side, their apices combined by a transverse 



continuous anastomosing vein ; sori unilateral, linear, paral- 



