ITAIONIITE^. — GIEIOHENIKB^. CTll. 



generic name — a mere change, since the former name does not 

 appear to have been pre-occupied, and was entirely set aside — 

 though sanctioned, or indeed, carried out, by high authority, and 

 with Dr. Wallich's concurrence, is unfortunately bad in prece- 

 dent, since no subsequent act can expunge from the records of 

 science a name once imposed ; and thus, what is now Matonia, 

 has an unnecessary synonyme. 

 Ex. : M. pectinata, S. Br. (Prionoptcris Parc[uhariana, Wall, olimj 



Order— V01jY70DJACEM. TW^e— aLEICHENINEJi;. 



151. PLATYZOMA, S. Brown, Frod. M. Nov. Soil 160. 



Sori non-indusiate, punctiform, consisting of few (2—4) sessile 

 spore-cases, which are soon deciduous, enclosed within the 

 reToluto-saccate pinnae ; the receptacles terminal on the veins. 

 Veins simple, incurvo-horizontal from a central costa, free, 

 externally obscure, prominent on the inner surface. 



Fronds narrow, linear, pinnate, rigid, csespitose; pinnse nu- 

 merous, minute, sessile, sub-orbicular-ovate ; the margins re- 

 markably rcTolute and glanduloso-ciliate, the under or inner 

 surface pulverulous. Khizome short, creeping. — Owing to the 

 minuteness and rigidity of the pinnse of this fern their structure 

 is not easily seen, but we have distinctly traced the veins, and 

 the insertion of the sori. The fertile pinnse are more convex, 

 and are often found split down the costa, thus divided into two 

 sub-hemispherical portions. The plant is peculiar in habit and 

 appearance, much more resembling Jmnesonia than Qleichenia, 

 from which latter, however, it is scarcely distinguishable in words, 

 or in strict characters. It is a particularly elegant little fern. 

 The spores are bluntly triangular. 



Ex, : P. microphyllum. It. Br. 



152. GLEICHENIA, Smiih.Mem. Acad. Twin. v. 419. 



Mebtbnsia, Willdenow ; DiCEAlfOPTEEls, Bemha/rdi; Caltmella, 

 Treat; Sticheeus, Preal; Hiceiopteris, Presl; Gleichewiasteum, 

 Fred; Plattzokatis sp., Deavaux. 



Sori non-indusiate, round, superficial or immersed, consisting 



x2 



