INTRODUCTION. 
Vaillant has described these plants under the name of Hepalica and Hepaticoides, but 
has added little to what Dillenius had done, except noticing, in many instances, the vaginae, 
and the quadrifid capsules. 
Our countryman, Ray, is more .particular in this respect. “Lichenastrum*,” he says, 
“est Musci genus fertile, vel, si placet, floribus insigne, cujus capitula longiusculis pediculis 
innascentia per maturitatem in quatuor plerumque aequales partes, cruciformem florem 
referentes, ad basin usque dividuntur, et farinam einittunt tenuissimain, apicum in floribus 
perfectioribus pollini respondentem, licet hie usus nec reliquis Muscis denegari queat, 
cum capitulorum pulvis similem prorsus figuram et structuram obtineat, si armato oculo 
examinetur. Ceterum simplicia et nuda sunt capitula, singula nempe singulis pediculis 
plus minusve longis insidentia, e vagina nunc simplici, nunc bivalvi, nunc in plures partes 
per summitatem divisa egredientibus, quibus a Lichene clarissime distinguitur hoc genus.” 
This, however, includes our genus Anthoceros, which forms his first division: “Lichen- 
astrum capitulis bifariam se aperientibus.” His second comprises our J unger mannicc ; 
“Lichenastrum capitulis in quatuor segmenta florida, tanquam totidem petala se aperi- 
entibus:” and this is subdivided into “Foliis varie et minus determinate divisis,” our 
Jungermamia f rondos# ; and “Foliis figur® magis determinat®,” comprising the J unger- 
mannia foliace a. 
Micheli, with his accustomed talent for discrimination, has divided the genus Junger- 
rnannia into three ; but has taken characters from the habit of the plant, rather than from 
the fructification, which unfortunately will not bear him out. Ilis first genus, Marsilea, 
(our J unger mannia j rondos#) “est plant® genus flore monopetalo, campaniformi, patente, 
in quatuor profundas partes dissecto, ac veluti quatuor petalis constare videtur, sed sterili, 
filamentis aut potius, cum clarissimo Columna, staminibus tenuissimis, et pulverulentis 
nunc in medio, nunc ad extremum donato. Idem calyce caret, et pediculo insidet, ac e 
vagina tubulata egreditur. Capsul® autem seininales perexigu® in plantis plerumque non 
floriferis, in nonnullis speciebus per totam foliorum superficiem, in aliis vero per eorum 
extremitatem occurrunt in quarum sinum unicum et rotundum habetur semen:” and this 
though it may at first sight appear the most natural of the three, yet is most variable 
in point of its fructification in the different species of which it is composed. With him 
the second genus, Jungermamia , is “a Marsilea diversum, foliis in surculis bino ordine 
Trichomanis et Polygonati more quodamtenus dispositis. Semina in externa plantarum 
parte extant;” and his third, “ Muscoides ,” he says, “est plant® genus ab Jungermannia 
discrepans surculis tribus, quatuor vel quinque foliorum ordinibus vestitis : inferiores vero 
ordines superioribus sunt valde minores. Semina non in externa foliorum parte sed 
recondito in sinu squamarum cujusdam fructus, qui locustarum Graminis arnoris formam 
pr® se ferens, per surculos vel per plantas non floriferas innasci solet.” Thus, in Junger- 
manma, this author has taken the gemm®, and in Muscoides and Marsilea, the anthers, for 
the seeds ; and has made the character depend, in a great measure, upon their respective 
situations. The capsule he considers a monopetalous, campanulate, sterile or male flower 
* Raii Syn. Stirp. Brit, ed. 3 . p, 109 . 
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