CHARACTERS OF TRIBES AND GENERA, B- 
Hymenophyllacee have a wide geographical range, 
abounding in the tropical regions of America and the West 
Indian Islands, in India, the Islands of the Indian and 
Pacific Oceans, and extending as far as New Zealand and 
Lord Auckland’s Islands in the southern hemisphere, and 
Norway and the Faroe Islands in the northern; but very 
Sparingly found on the African continent, They love 
Shade and moisture, many being epiphytal and clothing 
trees like moss, or growing in shady ravines or caves; 
but the same species often occurs under different influences, 
and consequently assumes different appearances, which has 
Jed to an unnecessary increase in the specific nomenclature. 
The number of species varies according to the views held 
by different authors, 172 are described in the “ Species 
Filicum,” and are nearly equally divided between the two 
genera, Hymenophylium and Trichomanes, which in the 
“Synopsis” are reduced to 149. 
This, however, falls far short of the number given by ` 
Dr. Van Den Bosch, who, in his “Synopsis Hymenophylla- 
cearum,” enumerates no less than 302 species, as already 
_ shown at page 31. 
199.—H wENornYrLUM, Sm. (1793). 
Vernation uniserial and sarmentose. Fronds varying 
from simple to decompound multifid, membranaceous and 
-~ pellucid, smooth, or bearing simple forked or stellate hairs. 
. Veins simple or forked, free. Sori terminal. Indusium 
"urceolate, bilabiate, or bivalved. Receptacle short, included ` ` 
within the indusium. | : 
^ Type. Hymenophyllum Tunbridgense, Sm. p. 
. lust. Hook. and Bauer Gen. Fil., t. 32; Moore Ind. 
Fil, p. 90, A. ; J. Sm. Ferns Brit. and For., fig. 137; 
.. Hook. Syn. Fil., t. 2, fig. 16. 
