FILICES. 65 



HriiExornTLLUM,' Smith, and 

 Trichomaxks,- Smith. 



Those two genera, separated by their fructificiition only, arc remarkable for 

 the delicate and translucent texture of their fronds, and have been called " filmy 

 ferns " in consequence. 



The fructification of ITi/menopJiiiUum is either terminal or lateral relatively 

 to the pinnae, or to the frond itself, if entire ; but it appeai-s always to end a 

 contracted segment of a divided frond, or the vein of an entire frond. The thcciE 

 are sessile or nearly so on a central receptacle, or columella, which looks like the 

 prolonged and thickened vein. The involucre is 2-lii)ped, formed of the same 

 substance as the frond itself. 



The fi-uctification of Trichomanes is very similar, but the involucre is undivided, 

 looking like a little urn, and the central a.xis, or columella, on which the theca; are 

 seated, is considei-ably prolonged, forming a seta — hair or bristle, — which peculiarity 

 has caused, if not all the species, at all events our single British one, to be called 

 The Bristle-fern. They both have slender thread-like (more rarely stout) creejiing 

 rhizomes, which love to hide themselves in the deep moss which clothes the lower 

 parts of trees, or among any loose vegetation which will provide them v\"ith the 

 moisture they reqiiire. Some have exceedingly minute and simple fronds — others 

 fronds a foot or more in length, and much divided. I have gathered about a doz(>n 

 species in all, but, I dare say, there are many more yet undiscovered. A British 

 species, Hi/menophi/llum Tiinhridijicnu, is among those gathered. A ])rotty little 

 Trichomanes, which I discovered many years ago at Henzui, and named Henzaiense 

 accordingly, appears in the Synopsis Filicum as the mutual discovery of a Mr. 

 Henzai and myself at Maulmain, in Pegu .' A larger and a widely distributed 

 species, 7'. Javanica, with fronds about 6 or 8 inches long and pinnated, which aro 

 tufted at the end of short rigid rhizomes, emitting long wiry roots, is a terrestrial 

 fern, frequently found on the banks of hill-streams. It is one of many fenis to be 

 found by the stream at Aladrecamam, ilcrgui, a delicious little bit of fern-hunting 

 ground. 



Space docs not admit of special description. 



Davallia,^ Sm. 



This genus furnishes about a dozen species, all trce-loviug, and never so happy 

 as when they can insert their long running rhizomes among the sheathing bases of 

 the huge leaves of the Palmyra or Talipot Palms, which often cling to the trunk 

 long after the leaves themselves have perished. Jlergui is rich in such trees — 

 indeed, I do not know that I have ever seen anything finer or nobler than a grove 

 of Corypha umhracalifera (Talipot), which is to be seen a little way in, behind the 

 town. On their trunks, as also on the numerous cocoa-nut trees all round about, 

 may be found in profusion IknalUa solida, I), elegans, J), btdlata, with many other 

 most interesting ferns. 



The Davallias have nearly all gracefully drdojiing and mnch-divided fronds on 

 scaly creeping root-stocks. Maulmaiu has furnished one new species : — 



D. HTiiENOPETXLA, Par. 

 D. Parishii, Hook. 



This species has fronds of so extremely delicate and semi-transparent a texture 

 that the name " iri/menDphi/lla'''' naturally suggested itself. The rhizome is short, 

 and not scaly. Stipes very slender and brittle ; " fronds flaccid, 6-9 inches by 4-6 

 inches, in outline deltoid, divided down to the rachis on the lower part; but not on 

 the upper. The lowest pair of pinna: arc broadest and most deeply cut on the lower 

 side ; \ovie%t pinnules reaching down nearly to the racHs, toothed more than half-way 



• Hymenophylluni. vnriv-fvo%, a tliin memtirano ; ami ()>i\\ov, a leaf. 



* Trichiimaiies. flplj-rpixis, a hair; and jao^ir, thiu (r), iu allusion to the thin bristle? 

 ' Davallia, presumably from a proper name. 



