ACROBOLBUS. 523 
Folia suceuba, oblique inserta ; inferiora subeontigua subquadrata, ad 4 
subacute bifida, angulata, segmentis divergentibus tenui-acuminatis 
acutis ; superiora inerescentia, magis conferta, latiora, laxe compli- 
cata, segmentis ineequalibus acuminatis, inferiore subrhombeo, supe- 
riore angustiore lanceolato-triangulari, margine crispata, angulata 
vel hie illie incisula, subinde basin versus utrinque hastatim uni- 
dentata ; cellule mediocres hexagonz, subleptodermes, endochromio 
sparso subopacee, folii mediam basin versus longiores, subrectangu- 
lares. 
Flores dioici: 9 terminales, demum innovatione suffulti. Folia sub- 
floralia latiora quam longa, amplexicaulia, seepius triloba, insigniter 
incisulo-crispa ; bracteze propriz juveniles, adhuc parve, profunde 
lobate. Pistillidia sub 10, receptaculo convexo purpureo insidentia. 
Ceetera desunt. 
Obs. In specimine Taylori archetypo, in monte Knockavohila Hibernize 
lecto, caulis pollicaris est, seepe furcatus. Folia ad $ (interdum solum 
ad +) usque biloba, lobis plerumque subacuminatis apiculo 3-4 cellulas 
longo auctis, sinu pro more obtuso, basi antica vix leniter recurvula ; cel- 
lule pariete tenui vel ad angulos vix incrassato. Bractez intime primum 
parve, demum magne, valde lobate laciniateeque, undulato-crispe. 
Marsupium obovato-globosum, valde carnosum, pariete 6—7-strato (calyp- 
tra inclusa, ad apicem usque marsupio adnata). Pistillidia 20 et plura, 
erecta, confertissima, subcylindrica, basi paulo dilatata. Pedicellus basi 
calceolo eyathiformi viridi 5-lobo receptus. 
Folia caulina, involucrum versus precipue, haud raro dente uno alte- 
rove marginali armata.—In receptaculo ? invenit el. Gottscheus pistil- 
lidia cum lobulis phylloideis (pistillidiis transformatis) mixta. 
This plant confronts us with a problem that admits of two solutions, 
and there are some others in similar case. The differences (which nearly 
always exist) between the tropical and the temperate form may to some 
observers appear adequate to justify their being held distinct species, 
while to others they will seem merely varietal ; although all will readily 
admit that, at some period more or less reraote, both forms have had a 
common ancestor. Jubula Hutchinsiw, Lepidozia eupressina, and Dumor- 
tiera hirsuta are some of the hepaticee, and there are several mosses, that 
leave us in the same dilemma. I have tried to decide all such questions 
from the evidence of structure alone, without any reference to geography. 
Thus, as to Acrobolbus Wilsoni, plants of the Andine form placed beside 
others of the European form, are in most respects so very like that, 
although the leaves of the former are more deeply cloven, and the 
segments are rarely so fine pointed, I cannot venture to separate them 
specifically. 
Subtribus VII. FOSSOMBRONIEA:. 
Plante vel foliose, post siceationem flaccid tenerrime, vel szepius 
frondosz ; prostrate, subsimplices vel dichotome, raro ramos (fron- 
dulas) e facie postica proferentes, rarissime basi rhizomatose. 
Caulis raro teres, plerumque subplano-convexus, in aliis tenuis, in 
aliis prelatus. Folia (ubi adsunt) succuba vel subtransversa, sat 
magna et lata, integra vel apice rude incisa. Frondes margine vel 
