HEPATIC^. 



L 390 ] 



IIEEPETIUM. 



of the capsules (PI. 40. fig. 35). TARGIONIA 

 has branched elaters. 



The spores mostly have a double coat, but 

 not always (e. g. Marchantia) ; they germi- 

 nate by protruding a pouch-like process, 

 which becomes a filament, from which the 

 new fronds or leafy stems arise. 



The peculiarities of the different groups 

 above referred to will be better understood 

 after reading the following characters. 



Synopsis of tlie Families. 



A. Vegetation frondose, i.e. leaf and stem 

 confounded. 



ANTHOCFROTE^J. The vegetative por- 

 tion consists of a minute green membranous 

 or slightly fleshy body growing on damp 

 ground, not exhibiting any distinct mid- 

 nerve : it is at once known by its peculiar 

 fruits or sporanges, consisting of slender 

 stalk-like bodies springing up irregularly 

 from the upper surface of the frond, which 

 forms little sheaths (vaginules) around their 

 bases. These stalk-like fruits burst when 

 ripe, splitting down the middle from the 

 tip, and display a central bristle-like column 

 (columella), to which adhere the minute 

 hair-like bodies (rudimentary elaters j which 

 are mingled with the spores. 



MARCHANTTEJE. The vegetative portion 

 is here also a succulent leaf-like expansion, 

 mostly exhibiting a more or less lobed 

 form, and without any conspicuous mid- 

 nerves in the lobes. The fruits are more 

 complicated structures than those of Antho- 

 ceroteaB. From notches in the lobed frond 

 arise slender stalks terminating at the top 

 in an expanded structure (receptacle), re- 

 sembling in some cases a conical cap, in 

 others a star with a number of thick rays 

 like the spokes of a wheel, &c. The spores 

 are formed in membranous sacs attached on 

 the under surface of the cap or star-like 

 body, and they are accompanied by elaters of 

 considerable size exhibiting highly deve- 

 loped spiral bands. he sporanges have no 

 columella, and burst at the tip with more or 

 lesa regular tooth-like valves. 



IlicciEJE. Vegetative portion an exceed- 

 ingly delicate cellular leaf-like structure, 

 more or less lobed, with an evident inid- 

 ' nerve. The sporanges are either imbedded 

 in the substance of the frond, or only ele- 

 vated on a very short stalk, and surrounded 

 by a membranous sheath derived from the 

 upper surface of the frond. The sporanges 

 have no columella and no elaters. 



PELLIEJE. Vegetative portion a leaf-like 

 frond, mostly with an evident mid-neme, 

 from which arises the sporanges, consisting 

 of capsules, usually bursting by four valves, 

 more or less elevated on a thread-like stalk. 

 Sporange without a columella j spores ac- 

 companied by elaters. 



B. Vegetation foliaceous, i. e. leaves and 

 stem distinct. 



JUNGERMANNIE^. Vegetative portion a 

 thread-like stem clothed with green mem- 

 branous leaves more or less overlapping at 

 their bases. Sporanges springing from the 

 end of the stem, raised on more or less 

 evident stalks, bursting by four valves and 

 spreading in the form of a cross; spores 

 with elaters, which often adhere to the 

 valves of the sporange. The leafy stem of 

 Jungermannieae is generally readily distin- 

 guishable from that of the Mosses by the 

 mode of insertion of the leaves, which pro- 

 duces a peculiar flattened arrangement. 



BIBL. Hooker, Br. Junger?nanni<e,18I6', 

 Bischoff, Nova Acta, xvii. 909, pis. 67-71, 

 1835; Entwickl. d. Lebermoose, Bot. Zeit. 

 xi. 113, Ann. Sc. Nat. 3 se"r. xx. 57 ; Lin- 

 denberg, Synops. Hepatic. 1814 ; Greenland, 

 Ann. Sc. Nat. 4 se"r. i. 5 ; Hofmeister, Vergl. 

 Unters. iib. Kryptog. 1851 ; Gottsche, Bot. 

 Zeit., Suppl. vi. 1858; Du Mortier, Hepat. 

 Europ. 1874; Carrington, Hepat. 1876; 

 Leitgeb, Leberm. 1879 ; Husnot, Hep. Gall. 

 1881. 



f HERCOTHE'CA, Ehr. A genus of fos- 

 sil Diatomacese. 



//. mammillaris (PI. 18. fig. 31), the only 

 British species; diameter 1-810". Bermuda. 



BIBL. Ehrenberg, Ber. d. Berl. Ak. 1844, 

 262 ; Kutzing, Sp. Ala. 27. 



HERMAN'NIA, Nicolet A genus of 

 Oribatea (Acarina). Cephalothorax without 

 ribs, soldered to the abdomen ; tarsi with 

 one claw. In moss. (Murray, EC. Ent. 221, 

 figs. ; Michael, Jn. Mic. Soc. 1880, 192.) 



HERPE'TIUM, Nees. A genus of Jun- 

 germannieae (leafy Hepaticae), distinguished 

 by the incubous bilcbed leaves not being 

 folded together, and by the obtusely three- 

 angled perigone. Two Brit, species : 



H. reptans(Lepidozia, Dumortier). Leaves 

 squarish, acutely two- or four-toothed at 

 the end. Woods and shady places. Jung, 

 reptans, Hook. Br. Jung. pi. 75. 



H. trilobatum (Mastigobryum, Nees). 

 Leaves ovate, three-toothed at the summit. 

 Moist alpine spots. J. trilobatum } Hook. 

 Br. Jung. pi. 76. 



