Musci Exorici.—Thouarsiani. 
JUNGERMANNIA RHIZOBOLA. 
Jungermannia stipitata, frondibus oblongis dichotomis 
nervosis, marginatis denticulatis, apice longissime at- 
tenuata radicante. (Tas. LXXXVIL.) 
J.rhizobola. Schwaegr, Musc. Hep. Prodr. p, 31. 
Has. In insula Borbonie. D. du Petit Thouars. 
Stipes semiuncialis, filiformis, subcompressus, flavescens. Frons 
ovato-oblonga, membranacea, pulcherrime reticulata, pallide 
virescens, pellucida, rarius simplex plerumque dichotome 
divisa, undulata, margine incrassata, dentato-serrata, denticu- 
lis distantibus, obtusa, vel plerumque in apicem filiformem ra- 
dicantem stipiti omnino simillimam sed multo longiorem atte- 
huata, nervo satis angusto, viridi percursa, 
This remarkable plant, of which the specimens so liberally com- 
municated to me by its discoverer, possess, 1 regret to say, no 
fructification, will rank, so far as can be ascertained by habit, with 
J. Lyelilii, J, hibernica, J. flabellata, and J. Hymenophyllum : 
differing from all, however, in the thicker noe of the fronds, 
a . s al. = | t1 f the ices, 
and especially in y “2 
which strike root into the out a are scarcely to be distin- 
guished from the stipes but by their greater length. 
M, du Petit Thouars had given to this plant the specific name 
of J. radicans; but besides that this appellation had been already 
given by some authors to J. ¢rilobata of Linneus, Schwaegrichen 
seems clearly already to have described this species in his Musc. 
Hepat. Prodromus, applying to it there the name rhizobola, 
though without mentioning by whom it was discovered. 
Fig. 1, plants, nat, size. Fig. 2, single plant.-magn. 
