Spruceane. N. O. Filices. 
DCCCCLXXXII. 
TRICHOMANES BICORNE, Zook. ° 
Caudice crassiusculo radicante, frondibus cespitosis rigidius- 
culis ovatis seu oblongo-ovatis tripinnatifidis subtus in costam 
longe sparse setosis, laciniis oblongis integris vel bifidis, 
involucris copiosis terminalibus obovatis in sinubus bifidis 
bicornibus segmentorum profunde immersis, receptaculo 
columellaque longiuscule exsertis, rachi alte alata. 
Has. Barra do Rio Negro, on logs or roots of trees, in dense 
moist forests, Amazon, (m. 1178.) and at St. Gabriel, Rio 
Negro, frequent on decayed logs on the Catingas, R. 
Spruce, Esq., n. 2334. 
This we cannot but consider an entirely new species, in 
some respects allied to T. alatum, Sw., yet considerably 
different. It is rather short, and firm and compact in its 
mode of growth, and varies from two to four or five inches 
high. The costa beneath is beset with dark strongish hairs 
or sete. But the remarkable feature is the involucre, which 
is sunk between the two horns as it were of the apex of a 
segment, and the apex of the segment and the sides of 
the mouth of the involucre, forming together, almost the 
letter V. Both the receptacle of the capsules and the columella 
are much exserted. 
Fig. 1. Fertile portion of a frond. f. 2. Involucre:— 
magnified, 
