A. W. Evans — JImcaiian Hepaticm of the Tribe Jnhuloidem. 397 



two species, although belonging to different subgenera, bear a 

 certain superficial resemblance to each other. In certain cases the 

 resemblance is still more marked from the fact that the lobule of F. 

 Aongstroemii is sometimes inflated throughout nearly its whole 

 extent, losing thereby its characteristic Cho^iayithelia-iovm, and 

 closely approaching the lobule of F. Sandvicensis. These facts, 

 together Avith the great rarity of the perianths in F. Sandvicensis, 

 might easily account for the two having been confused. Even with- 

 out their very characteristic perianths, however, there are good 

 points of distinction between the species. The strongly cordate base 

 of the lobe in F. Sandvicensis, the broad, emarginate and cordate 

 underleaves, and the very conspicuous thickenings of the leaf-cells 

 are quite unlike what we find in F. Aongstroemii. 



In Frullania arietina Tayl., of tropical and subtropical America, 

 F. Aongstroemii finds a close ally. It differs from this species in its 

 autoicous, not paroicous inflorescence, in the entire margins of its 

 bracts, which are less highly connate with the bracteoles, and in the 

 different shape of its lobules. It will be remembered that Austin* 

 has already reported F. arietina from the Hawaiian Islands as 

 growing with his Dendroceros Clintoni. Mixed with the specimens 

 of this last species from Mr. Pearson's collection, I find a few sterile 

 stems of F. Sandvicensis but no other Frullania, so that it is prob- 

 able that Austin's determination was incorrect. Another species of 

 tropical America, F. gibbosa Nees, resembles F. Aongstroemii in its 

 autoicous inflorescence and entire bracts, but it differs in its squar- 

 I'ose, densely imbricated leaves, with much larger lobule and large 

 disc-like stj'lus, in its broader underleaves, cordate at the base and 

 less deeply bifid at the apex, and in its more pointed perianths. 



II. Subgenus Tkachycolea Spruce. 



2. Frullania Oahuensis Hampe. 



Frullania Oahiiensis Hampe; G. L. & N. Nova Acta Acad. Leop.-Car. 

 xix, suppl. 1, 471. 1843. 



Plate XLIV., figs. 12-19. 



Dioicous : plants closely appressed to substratum, scattered or 

 forming loose thin mats, reddish- or brownish-green, sometimes 

 almost black: stems irregularly pinnately branched: leaves imbx-i- 

 cated^ the lobe ovate, somewhat convex, arching over the stem and 

 slightly cordate at base, rounded at the apex, entire; lobule galeate, 



* Bull. Torr. Bot. Club, v, 15. 1874. 



Trans. Conn. Acad., Vol. X. March, 1900 



27 



