HEPATICACLA. 705 
small, oval, globular, or flasked-shaped, cellular sacs (fig. 831), 
situated in the axils of leaves, or immersed in the frond, or 
imbedded in the upper surface of peltate or discoid stalked 
receptacles (jig. 830, 7). The archegonia (fig. 833) are usually 
somewhat flask-shaped bodies, which are imbedded in the fronds, 
or contained in receptacles (fig. 832, +) which are elevated on 
stalks (fig. 832, s) above the thallus. Each archegonium de- 
velopes after fertilisation a sporangium, which either bursts by 
valves (fig. 1123) or teeth, or by irregular fissures. The spor- 
angium is usually without a columella, and contains spores 
Pre. 1122: Prey li23: 
Fig. 1122. Jungermannia bi- 
hy dentata. The stem is creep- 
[Z ing, and bears numerous 
s\h fe small imbricate leaves. 
22 > Fig. 1123. Sporangium of 
x SAK | \ Xe StS Jungerminnia hyalina, de- 
0 i re hiscing vertically by 4 
OP, iW RS valyes, and  ccntaining 
spores in its interior. 
mixed with elaters (jig. 834); or it is furnished with a thread- 
like columella, and coutains spores and no elaters, or the latter 
are imperfect ; or it has neither elaters nor columella. 
Division of the Order and Illustrative Genera.—This order 
may be divided as follows :— 
Sub-order 1. Jungermanniaceer or Jungermanniex, Scale- 
mosses.—Sporangia oval ; without a columella ; splitting ver- 
tically by 4 valves (fig. 1123). Spores mixed with elaters. 
Iilustrative Genera :—Blasia, Micheli; Jungermannia, Dillen. 
Sub-order 2. Anthocerotex.—Sporangia pod-shaped ; 1— 2- 
valved ; with a filiform columella. Spores either mixed, with 
imperfect elaters, or these are absent. Illustrative Genera :— 
Anthoceros, Micheli; Monoclea, Hook. 
Sub-order 3. Marchantiaceex or Marchantiex, Liverworts. — 
Sporangia without valves ; bursting irregula1ly or by teeth ; 
without a columella. Spores mixed with elaters (fig. 854). 
Illustrative Genera :—Fimbriaria, Nees; Marchantia, March. 
Sub-order 4. Ricciacee or Ricciex, Crystalworts.—Sporangia 
without valves; bursting irregularly ; without a columella. 
3 C2 
