JANIA. 

 J. 



[ 371 ] 



JANIA, Lamouroiix. A genus of Coral- 

 linaceae (Florideous Algae), calcareous fila- 

 mentous bodies, occurring in tufts, pale red 

 or purplish when fresh, on small Algae be- 

 tween tide-marks. The filaments are arti- 

 culated and dichotomously branched, impreg- 

 nated with a calcareous deposit. The fruit 

 consists of urn-shaped ceramidia, formed out 

 of the end joints of the branches, a dichoto- 

 mous continuation of which is represented 

 by a pair of minute divergent horns on the 

 ceramidium ; the latter is pierced by a pore 

 at the apex, and contains a tuft of erect 

 linear tetraspores. British species : 



1. J.rubens. Joints of principal branches 

 cylindrical. Harvey, Phyc. Brit. pi. 252. 



2. J. corniculata. Joints of principal 

 branches obconical and compressed, /. c. 

 pi. 234. 



BIBL. Harvey, /. c. and Brit. Mar. Ala. 

 p. 107. pi. 13 D. 



JATROPHA. See CASSAVA. 



JENKINSIA, Hook. A genus of Tzeni- 

 tidese (Polypodaeous Ferns). Exotic. 



JUNGERMANNIA, Dill. A genus of 

 Jungermannieae (Hepaticaceae), formerly 

 including the whole of these plants, but 

 now restricted to a certain number of species, 

 thus characterized : Fructification terminal. 

 Perichaetial leaves free or united only at the 

 base, like or unlike the stem-leaves. Peri- 

 gone membranous, tubular, plaited-denticu- 

 late at the apex, the mouth 3- or 6-cleft. 

 Vaginule membranous, included or rarely 

 exserted. Capsule 4-valved, splitting to the 

 base. Amphigastria present or absent. 



This is the largest genus of the Jungerman- 

 nieae ; among the commonest species are J. 

 bicuspidata, L., J. albicans, L., J. barbata, 

 J. setacea, &c., found on wet bogs, banks, 

 rocks, &c. 



BIBL. Hooker, Brit. Jungermanniea, Brit. 

 Flor. i. pt. 1. p. 112, &c.; Ekart, Synops. 

 Jungermann.', Nees v.Esenbeck, Lebermoose ; 

 Gottsche, Lindenberg and Nees, Synops. 

 Hepatic. Hamburg, 1844-47. 



JUNGERMANNIEAE. A family of He- 

 paticae, distinguished by possessing a distinct 

 stem, bearing leaves, often with stipule-like 

 bodies called amphigastria (fig. 384), with 

 terminal archegones and sporanges, bursting 

 by four valves (figs. 324 and 325), destitute 

 of a columella, containing elaters mixed with 

 the spores. In the older works, the tribe 

 comprehended only the genus Jungermannia, 

 in which were also included the Pellieae, but 

 Jungermannieae, as restricted to leafy stemmed 



JUNGERMANNIE.E. 



Fig. 384. 



Jungermannia albicans. 



Stem with succubous leaves and amphigastria, and a 

 lateral unopened perigone. 



Magnified 10 diameters. 



Liverworts, is now broken up into a number 

 of genera. 



Synopsis of British Genera. 



1. Leaves incubous (their bases covered by 

 the tips of those below). 



* Leaves complicate, two-lobed. 

 j* Amphigastria present. 



I. LEJEUNIA. Perigone terete or an- 

 gular. Leaves not ciliated. 



II. PHRAGMICOMA. Perigone depressed- 

 plane, subcordate, obtusely keeled in front. 



III. FRULLANIA. Perigone compressed- 

 keeled. 



IV. MADOTHECA. Perigone compressed, 

 two-lipped. 



V. PTILIDIUM. Perigone terete. Leaves 

 ciliated. 



VI. TRICHOCOLEA. Perigone wanting. 

 Leaves capillary-multifid. 



t Amphigastria absent. 



VII. RADULA. Perigone compressed. 

 ** Leaves not complicate, two-lobed. 



t Amphigastria present. 



VIII. SENDTNERA. Perigone six-angled, 

 tubular, deeply multifid. 



IX. SCHISMA. Perigone plicate, the 

 mouth almost equally erecto-laciniate, co- 

 vered by the perichaete. 



X. HERPETIUM. Perianth triangular, 

 long, toothed at the mouth. 



XI. CALYPOGEIA. Perianth oblong, sac- 

 like, fleshy, hairy, truncate, attached by one 

 side of its mouth to the stem. 



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