FISSIDENS. 



[ 325 ] 



FLAX. 



olated, often very papillose, produced at the 

 back and point into a lamina beyond the 

 leaf (figs. 243-246), whence three parts 

 are distinguished in the latter : 1, the 

 true horizontal blade ; 2, the dorsal lamina, 

 arising vertically from the back of the nerve; 

 3, the apical lamina, the preceding lamina 

 produced beyond the true horizontal blade 



Fig. 244. 



Fig. 247. 



Fiasidens bryoides. 



Figs. 244, 245, 246. Sections of 243, at various heights 

 from the base. 

 Fig. 247. Fragment of peristome. Magn. 100 diams. 



of the leaf in a two-edged form, on each 

 side of the nerve. Capsule equal, rarely 

 annulate. British genus : FISSIDENS. 



FIS'SIDENS, Hedw. A genus of Fissi- 

 denteee. Character that of the family. In- 

 florescence monoecious or dioecious, terminal 

 on the main stem or on short secondary 

 branches. Montague has separated the 

 species with an entire calyptra under the 

 generic name of Conomitrium. 



F. bryoides (fig. 241), not uncommon, is 

 a most elegant little moss. 



BIBL. Wilson, Bryol. Brit. p. 301. 



FISSURI'NA, Reuss. A compressed 

 Lagena, with slit-like aperture. It has the 

 same relation to Lagena that Lingulina has 

 to Nodosaria. 



BIBL. Reuss, Monogr. Lagen. in Sitz. 

 Ak. Wiss. Wien, xlvi. i. 1863. 



FISTULI'NA. A genus of Polyporei 

 (Hymenomycetous Fungi), characterized by 

 the papillae of the fleshy hymenophorum 

 being at length elongated and forming 

 distinct tubes, which call to mind those 

 of Solenia. 



Fistulina hepatica occurs not unfrequently 

 on old oaks, on which it sometimes attains 



an enormous size, and when well dressed is 

 excellent for culinary purposes. The flesh, 

 when cut resembles that of beet-root. 



BIBL. Huss. i. t. 65; Berk. Outl 257, 

 tab. 17. fig-. 1 ; Cooke, Handb. 292. 



FLABELLI'NA, D'Orb. One of the 

 Nodosarince. It is dimorphous that is, 

 having two successive plans of growth : 

 the first spiral, like that of Cristellaria ; the 

 later rectilinear, like that of Nodosaria, or 

 rather of Frondicularia, which latter it 

 resembles in its chevron-shaped flattened 

 chambers. It differs from Frondicularia in 

 an eccentricity, or tendency to coil, in the 

 earliest chambers, and thus connects the 

 Stichostegian with the Helicostegian groups. 

 It is to Frondicularia as Vaginulina, Mar- 

 gmulina, and Planularia are to Nodosaria. 

 To many large flat Cristellarice (C. cassis) 

 semigeniculate chambers give a Flabelline 

 feature ; but pure Flabettince are rare in the 

 recent state (Batsch figured one) and in 

 Tertiary strata. In the Chalk (Ft. ruaosa, 

 PI. 23. fig. 38), Gault, Lias, and other 

 Secondary strata, Flabelline abound. 



BIBL. D'Orbigny, For. Foss. Tien. 92; 

 Morris, Brit. Foss. 35 ; Parker and Jones, 

 Ann. N. H. 3. xii. 136 ; Carpenter, Introd. 

 For. ICO, 164. 



FLAGELLA'TA. See INFUSORIA. 



FLANNEL, NATURAL. This term 

 has been applied to sheets or layers of a 

 harsh fibrous texture, sometimes found 

 covering meadows, rocks, &c. after an inun- 

 dation. It consists of the interwoven fila- 

 ments of Confervse, with adherent or en- 

 tangled Diatomaceae, Infusoria, crystals of 

 carbonate of lime, &c. To the naked eye 

 it closely resembles a piece of coarse or 

 loosely woven cloth. Similar layers are 

 frequently found upon the margins of pools 

 during the summer. As the water evapo- 

 rates, the Confervas and other organisms 

 remain supported upon the stems of rushes, 

 or blades of grass, and, when dry, form the 

 yellowish, greenish, or greyish layers of the 

 so-called natural flannel. 



See PAPER, METEORIC. 



FLAX. The liber-fibres from the stems 

 of the Flax-plant, Linum usitatissimum(nsk. 

 ord. Linacese, Dicotyledons). Under the 

 microscope, the fibres (PI. 28. fig. 2) are 

 readily distinguished from those of Cotton 

 by the form and consistence, being round 

 and attenuated to a point at each end, and 

 of a firm woody consistence, which prevents 

 them from collapsing, and having pits in the 

 wall. New-Zealand Flax is a totally differ- 



