FISSIDEXS. 



[ 325 ] 



FLAX. 



olatecl, often very papillose, produced at the 

 back and point into a lamina beyond tlie 

 leaf (tigs. 24o-24(J), whence three parts 

 ai'e distinguished in the latter : — 1, the 

 true liorizoutal 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. 



Fig. 245. 





Tnonnnnnnnnr-ii u ' 



Fissidens bryoides. 



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

 from the base. 

 Fig. 247. Fragment of pei-istome. Magn. 100 diams. 



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

 side of the nerve. Capsule equal, rarely 

 annulate. British genus : Fissiiien.s. 



FIS'SIDEXS, Hedw.— A genus of Fissi- 

 dentese. Character that of the family. In- 

 florescence moncecious or dioecious, terminal 

 on the main stem or on short secondary 

 branches. Montague has separated the 

 species w-ith an entire calyptra under the 

 generic name of ConomUrium. 



F. Im/oides (tig. 241), not imcommon, is 

 a most elegant little moss. 



BiBL. Wilson, Bnjol Brit. p. 301. 



FISSURI'NA, Reuss. — A compressed 

 Layena, with slit-like aperture. It has the 

 same relation to Layena that Linr/ulina has 

 to Nodosaria. 



BiBL. Reuss, Monogr. Lagen. in Sitz. 

 Ak. Wiss. Wim, xlvi. i". 18G3. 



FISTULI'NA.— A genus of Polyporei 

 (Hymenomycetous Fungi), characterized by 

 the papillaj of the fleshy hymenophorum 

 being at length elongated and forming 

 distinct tubes, which call to mind those 

 of Solenia. 



Fistulina heputica occurs not imfrequently 

 on old oaks, on which it sometimes attains 



an enormous size, and when well dressed is 

 excellent for culinai'v purposes. The flesh 

 wlien cut resembles tliat of beet-root. 



BiBL. IIuss. i. t. Go; Berk. Outl 257, 

 tab. 17. fig. 1 ; Cooke, Ilamlh. 292. 



FLABELLI'NA, D'Orb.— One of the 

 K(>(hisariu<e. It is dimorphous — that is, 

 having two successive plans of growth : — 

 the first spiral, lOce that of CristeUaria ; the 

 later rectilinear, like that of Nodosaria, or 

 rather of Frondicidaria, which latter it 

 resembles in its chevron-shaped flattened 

 chambers. It differs from Frondicidaria in 

 an eccentricity, or tendency to coil, in the 

 earliest chambers, and thus connects the 

 Stichostegian with the Ilelicostogian groups. 

 It is to Frondictdaria as Vayimdina, Mar- 

 gimdina, and Plunidaria are to Nodosaria. 

 To many large flat C'risteUarife ( C. cassis) 

 semigeniculate chamber give a Flabelline 

 feature ; but pure FlubeUime are rare in the 

 recent state (Batsch figured one) and in 

 Tertiary strata. In the Chalk (Fl. n/yosa, 

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

 Secondary strata, Flahellince abound. 



BiBL. D'Orbigny, For. Foss. Vicn. 92 ; 

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

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

 For. 100, 164. 



FLAGELLA'TA. See Infusoria. 



FLANNEL, NATURAL.— This term 

 has been applied to sheets or layers of a 

 harsh fibrous textvu'e, sometimes found 



covering meadows, 



rocks, &c. after an inun- 



dation. It consists of the interwoven fila- 

 ments of Confervas, with adherent or en- 

 tangled Diatomacese, Infusoria, crystals of 

 carlDonate 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 Confervse and other organisms 

 remain supported upon the stems of rushes, 

 or blades of gi-ass, and, when dry, form the 

 yellowish, greenish, or gi'eyish layers of the 

 so-called natural flannel. 



See Paper, meteoric. 



FLAX. — The liber-fibres from the stems 

 of the Flax-plant, Linum usitcdissimum(jx&t. 

 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 wood}' consistence, which prevents 

 them from collapsing, and having pits in the 

 wall. New-Zealand Flax is a totally differ- 



