CRyPTOGAMIA. 



48/ 



£>f which some of the latter have neverthe- 

 less a spurious vestige. All the former, 

 and some of the latter, are dorsiferous, 

 bearing fruit on the back of the frond, and 

 of these the fructification is either naked, 

 or else covered with a membranous invo- 

 lu crura, The genera are distinguished 

 by Linnseus 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 involucruni, and 

 especially the direction in which it bursts. 

 See Tracts relating to Nat Hist, 215. 1. 1. 

 Poh/podium, Engl Bot. t. 1149, has 

 noinvolucrum; Aspidium^ 1. 1458 — 1461, 

 has a single, and Scolopendrium y t. 1150, 

 a double one. Osmunda, 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. Botry- 

 chium 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- 



