HYMENOPHYLLACEiE. 



[ 334 ] 



HYPHOMYCETES. 



hymenium covering the tips and sides of 

 them. 



6. Tremellini. Sporange vague, or 

 cup-shaped, often gelatinous at first, harden- 

 ing by drying uj). Hymenium confounded 

 with the structure of the sporange, on the 

 upper, under, or both surfaces ; basidia ter- 

 minating the branches of hymenial filaments, 

 accompanied sometimes by branches bearing 

 spermatia. The detached spores often lie 

 imbedded in the gelatinous surface of the 

 hymenium, and sometimes produce spermatia 

 there. 



BiBL. Berkeley, Lindley's Vegetable 

 Kingdom, Hooker's Brit. Flora, vol. ii. pt. 2, 

 Ann. Nat. Hist. i. 81, and ix. p. 1; Leveille, 

 Ann. des Sc. nat. 2 ser. viii. p. 321 ; Fries, 

 Summa Veget. p. 267 ; Tulasne, Ann. des Sc. 

 nat. 3 ser. xix. p. 193. 



HYMENOPHYLLACEiE.— A family of 

 Ferns, distinguished by the delicacy of the 

 structure of their leaves and the composition 

 of the sori or fruits. The leaves are of the 

 utmost simplicity of organization, consisting 

 merely of a single layer of cellular tissue, 

 traversed by scalariform tubes constituting 

 the veins. There is no distinction of epi- 

 dermis and parenchyma, and no stomates. 



Genera. 



L Trichomanes. Sporanges sessile around 

 the base of an exserted filiform column, 

 formed by the })rolongation of a vein beyond 

 the margin of the leaf, surrounded by a cup- 

 shaped indusium continuous with the leaf 

 (fig. 343). 



Fig. 343. 



Fig. 344. 



Trichomanes humile. Hymenophyllura bivalve. 



Fig. 343. Fraccment of a leaf, with sori. 

 Fig. 344. Ditto. 



Magnified 10 diameters. 



IL Hymenophyllum. Sporanges sessile up 

 to the summit of a similarly formed column 

 projecting from the margin of the leaf, sub- 

 elevated, but not exserted beyond the indu- 

 sium, which is two-valved (fig. 344). 



in. Loxsoma. Sporanges stalked, in- 

 serted up to the summit of a sub-elevated, 

 exserted column arising in a similar way 

 within the margin of the leaf, surrounded by 

 an indusium, somewhat within the margins 

 of the fissures between the teeth of the leaf, 

 with a truncated mouth, entire. 



HYMENOPHYLLUM, Smith. — Filmy 

 Ferns. The typical genus of Hymenophyl- 

 laceous Ferns, remarkable for their delicate 

 structure and often almost moss-like habit. 

 Two dwarf species are natives of Britain, 

 H. tunhridgense and H. Wilsoni. 



Fig. 345. 



Fig. 346. 



Hymenophyllum ciliatum. 



Fig. 345. Fragment of a leaf. Magn. 10 diams. 

 Fig. 346. Sorus with one valve removed. Magn. 20 



diams. 

 Fig. 347, Sorus. Magn. 20 diams. 



HYPEROMYXA, Corda. See Cheiro- 



SPORA. 



HYPHEOTHRIX, Kiitz.-A genus of 

 OsciLLATORiACE^ (Confci'void Algae). No 

 British species recorded. 



HYPHOMYCETES.— An order of Fungi 

 composed of microscopic plants, growing as 

 moulds over dead or living organic sub- 

 stances. The vegetative structure or myce- 

 lium creeps over or among the structures 

 infested as a collection of delicate, simple or 

 branched, continuous or septate filamentous 

 cells (Jlocci), and produces the spores either 

 on lateral pedicels (fiom which they soon 

 fall off, becoming intermingled with the my- 

 celium), or in heads at the swollen or rami- 

 fied extremities of usually erect filaments 



