C»YPTOOAM-lA\ 4S7 



of which some of the latter liave neverthe- 

 less a spurious vestige. All the former, 

 and some of the latter, are dorsiferous, 

 bearing fruit on the back of the frond, mid 

 of these the fructification is eitlier naked, 

 or else covered with a membranous invo- 

 lucriun. The genera are distinguished 

 by Linnaeus according to the shape and 

 situation of the spots, or assemblages of 

 capsules, besides which I have first found 

 it necessary to take into consideration the 

 absence or presence of the involucrum, and 

 especially the direction in which it bursts. 

 See Tracts re/dting to Nat. Hist. 215, t. 1. 

 Poh/podiiim, Efig/, Bot. t. 1149? has 

 no involucrum; Aspidhini, t. 1458 — 1461, 

 has a single, and Scolopendrium, t. 1150, 

 a double one. Osmiindd, t. 209, has been 

 remarked by Professor Swartz to have a 

 spurious ring. It is one of those ferns the 

 lobes of whose frond are metamorphosed, 

 as it were, into spikes of capsules. Botri/- 

 chiam of Swartz, more distinctly spiked, 

 and having no vestige of a ring, is sepa- 

 rated by him from Osmunda. See one spe- 

 cies of it in Engl. Bot. t. 318. Ophioglos- 



