1115 



S. cuspidatum (Ehrh.) has the cartilaginous margins of the leaves 

 reflexed and wavy when dry ; the shape of the leaf is narrower than 

 in S. acutifolium ; often very long and tapering in the aquatic state 

 named S. plumosum. A less common species than the last. 



Besides these characters, by which the species may be known, 

 there are others consisting in the different form of the perichaetial 

 leaves, whereby S. squarrosum, cymbifolium and acutifolium are very 

 obviously separated from each other : the others I have but partially 

 examined. Differential characters are found also in the texture of 

 the walls of the capsule. 



It is hoped that these hints may seiTC as a satisfactory reply to Mr. 

 Sidebotham's request for information upon the subject, (Phytol. 871). 

 I shall feel obliged by the communication of specimens of any Sphag- 

 num which cannot be recognized as belonging to the species here 

 enumerated as British. It is highly probable that additional species 

 will be discovered, especially S. tenellum, Pers., now that the subject 

 is rendered accessible to the readers of ' The Phytologist.' 



W. Wilson. 



Warrington, September 27, 1844. 



Art. CCXLVI. — Notice of PresPs ' Hymenophyllaceo!.'' 



(Concluded from p. 1106). 



Genus, Sph^rocionium, Presl, 



"Costa teres, promiuula. Vente pinnatse, alternae, distantes, simplices ramosaeque, 

 steriles venulisque conformibus apice liberodesinentes. Sorus in lacinia frondis termi- 

 nalis, compresso-planus, sessilis. Indusiura bifidum, laciniis ovato-orbiculatis oblusis, 

 appressis, demum patentibus. Receptaculum indusio brevius, inferne cylindricum nu- 

 dum, apice globoso-incrassatum et capsuliferum. Capsulas lenticulares, oblique stipi- 

 tatse. Rhizoma repens, tenuiter filiforme, ramosum, ssepe praster radices alternas fili- 

 formes simplices ramosasque radiculispaleEefonnibuspiliformibus copiosissimis instruc- 

 tum. Frondes stipitatae, liygroscopicaB, tenerae vel tenerrimae, sparsae, plus minus in 

 rhizomate distantes, transparentes, pinnatim divisae, aut pilis apice stellatim ramosis 

 (umbraculiformibus) praesertim in costis venis margineque ornatse, aut sinuato-serrula- 

 tae, serratiiris subinde pilis simplicibus superatis, aut glaberrimas, paginis conformibus. 

 Stipes variae lougitudinis, teres. Raches teretes, utrinque prominulaj, ssepe una cum 

 stipite margine foliaceo alatee. Costae teretes, prominulae. Vense pinnatim exorien- 

 tes, alternae, simplices aut seepe ramosae, internae venulisque apice libero desineutes. 

 Parenchyma e cellulis hexagonoideis constitutum, tenerum. Sorus in dente laciniave 

 frondis terminalis, solitarius, sessilis, compresso-planus vel disco convexiusculus, par- 

 vus Indusium e laminis frondis disjunctis formatum, fronde multo tenerius, e eel- 



