Hymenophyllum . ] 
FERNS. 
49 
shining, rigid, purplish-black, without pinnae on the lower part. 
Pinnae alternate, in young fronds lobed only, afterwards pinnate. 
Pinnules wedge-shaped, crenate or cleft at the top, alternate. Sori 
marginal, in spots, one near the end of each lobe of the pinnule, the 
apex of which is turned over, forming a white, oblong cover, to 
which the fruit itself is attached. 
The manner of the expansion of this plant is very singular and interesting. 
The young frond is but slightly circinate in vernation, appearing at first with 
only one or two small, wedge-shaped pinnules ; after a time these ?plit into 
lobes, which lobes become wider, long-stalked, and detached from each other, 
forming separate wedge-shaped pinnules exactly similar to those from which 
they were detached, and if the plant be luxuriant, these again divide in a 
similar manner ; thus some fronds are found pinnate, others twice, and some- 
times thrice pinnate. The whole plant forms an interesting object for the 
microscopo, particularly the membranous indusium, which is beautifully veined. 
The ring of the theca also is very different from that of any ether British 
Fern. ( See plate of Genera.) 
"V in. — The properties of Adiantum are very uncertain. Its use is said to 
give name to the syrup Capillaire. It has neither fragrance nor flavor, and 
when boiled yields only a little mucilage. 
Hab. — P ort Kerig, Glamorganshire (verified 1834). Banks of the Carron, 
a rivulet in Kincardineshire, Professor Beattie. In a srfiall cave on the cast 
side of Carrach Gladden, a cove on the north coast of Cornwall, between 
Hayle and St, Ives, Professor Henslow. Isles of Arran, county of Galway, 
Dr. Osborne. At Wrisbeg, on a rock facing south-west on the shore of Loch 
Bulard, Mr. C. C. Babington. 
Geo. — South Europe, Isles of Bourbon, Teneriffe, Jamaica, & Hispaniola. 
HYMENOPHYLLUM, Swz. FILMY FERN. 
(upiv, a membrane, fvXXov, a leaf; or the membranous-leafed Fern.) 
PLATE OF GENERA, FIG. X. 
In this small and, delicate genus, a lobe of the pinna is contracted into the 
fruit and its receptacles , the lamina of the lobe forming two valves, enclosing 
between them the midrib, to near the end of which are attached several ringed and 
petioled tliecce, the annulus of which does not coincide with the petiole. 
1.— HYMENOPHYLLUM TUNBRIDGENSE. 
TUNBRIDGE FILMY-FERN. 
(Plate 4, fig. 4.) 
Cha. — Frond pinnate. Pinnre pinnatifid, erect. Lobes serrated. 
Rachis winged. Involucre orbicular, serrated at the top. 
Syn. — Hymenophyllum Tunbridgense, Smith, XVJld., Hook., Mack., Swz., 
Gray. — Tricliomanes Tunbridgense, Linn., Huds., With., Bolt., Lightf. 
— Tricliomanes pulchellum, Salisb. 
Fig. E. B. 162. — Hook, in Flo. Lon. 71. — Bolt. 31. — Flo. Dan. 954. — 
Hedw. 3. — Forst in Flo. Tonb. (excellent.) 
Des. — Root black, fibrous, hairy, extensively creeping, rather 
