CHAEACTEES OP TRIBES AXD GENEEA. 3io 



Hijmenophyllacea have a wide geograpliical 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 g-rowing in shady ravines or caves ; 

 but the same species often occurs under different influences, 

 and consequently assumes different appearances, which has 

 led to an unnecessary increase in the specific nomenclature. 

 The number of species varies according to the views held 

 by cliflTerent authors, 1 72 are described in the " Species 

 lilicum," and are nearly equally divided between the two 

 genera. Hymen opliyllnm 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 " Sjmopsis Hymenophylla- 

 cearum," enumerates no less than S02 species, as already 

 shown at page 31. 



199. — Htmenophyllum, Sm. (1793). 

 Vernation uniserial and sarmentose. Fronds varying 

 from simple to decompound multiiid, membranaceous and 

 pellucid, smooth, or bearing simple forked or stellate hairs. 

 Veins simple or forked, free. Sori terminal. Indusium 

 urceolate, bilabiate, or bivalved. licceptacle short, included 

 within the indusium. 



Type, HijmenophyUwm Tunhridgensr, Sm. 

 Illust. 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. 



