47. Genus AULACOMNION, Schwcegr. 
Whole Plant — Perennial, frequenting boggy and marshy places and moist places in woods, caespitose branched, from J an. 
inch, to 4 inches in height, pale green or yellowish-brown. 
Stem — Slender, more or less branched, having numerous reddish radicles. 
Leaves — Lanceolate, obovate, obtuse, entire, crowded or spreading ; margin revolute, serrate at the apex ; nerve ceasing 
below the apex ; areolae round, dot-like. 
Inflorescence — Dioicous. 
Barren Floiver (Antheridia) — Discoid or gemmiform, terminal or axillary, oblong. 
Fertile Flower (Archegonia) — Terminal. 
Vaginula — Oblong. 
Capsule — Cernuous, somewhat inclined, ovate or oblong, striate, reddish-brown, fruit stalk solitary, red. 
Calyptra — Oucullate, small. 
Operculum — Conical, rostellate. 
Peristome — With 16 yellow-brown teeth, equidistant, with narrow crowded transverse bars ; inner teeth pellucid, 
divided in the middle, and exhibiting 16 processes alternately. 
Annuhis — " Compound." 
Spores — Eound, small, yellowish. 
General Habitat — Boggy heaths, marshes, and moist sandy places in woods. Fruit : — May and June. 
Species Illustrated — Aulacomnion palustre (Sohwaegr). 
Reference to Plate — a, Fertile plant, natural size ; aa, Barren plant, natural size ; h, Stem leaf, X 2-in. ; 66, Branch leaf, 
X 2-in; c, Teeth of peristome, X 1-in. ; d, Operculum, X 1-in.; /, Capsule, X 2-in.; ff, Portion of 
same, X 1-in. 
, This genus is represented in Britain by two species. 
48. Genus ORTHODONTIUM, Schw. 
Whole Plant— Perennial, beautiful slender plants growing on rooks in bright green tufts with terminal fruit. 
Stem — ^ Slender, fragile, branched. 
Leaves — Long, linear, setaceous, crowded, or spreading ; margin plane ; nerve faint, ceasing below the apex ; areolae lax, 
narrow, oblong. 
Inflorescence — Monoicous. 
Barren Flower (Antheridia) — Numerous, gemmiform, with filiform paraphyses. 
Fertile Flower (Archegonia) — Few, with filiform paraphyses. 
Vaginula — Cylindrical. 
Capsule — Somewhat inclined, clavate, of thin texture, gradually tapering into the pale red curved fruit stalk; 
cellules lax, yellowish-green. 
Calyptra — Cucullate, small. 
Operculum — Conical, beaked. 
Peristome — Double, with 16 outer teeth, erect, very similar to Bryum ; teeth of the inner peristome alternate, 
resembling in form the outer ones, pellucid. 
Annulus — " Eudimentary." 
Spores — Yellow, small. 
General Habitat — Sandstone rocks, Cheshire, Yorkshire, Sussex. Fruit : — March. 
Species Illustrated — Orthodontium gracile (Sohwaegr), Bryum graoile (Wilson), in Eng. Flor. t. 2835. 
Reference to Plate — a, Plant, natural size ; aa, Same, X 2-in. ; 6, Stem leaf, X 1-in. ; 65, Same, X 2-in. ; c, Basal 
cells of leaf, X i-in. ; d, Operculum, X 1-in.; e, Vaginula, X 1-in.; /, Portion of capsule, showing the 
columella, X 1-in.; Teeth of peristome, x i-iu. 
This genus is represented in Britain by the species figured. 
49. Genus LEPTOBRYUM, Wilson. 
Whole Plant — Annual, growing in patches, fruit terminal, about 1 inch in height, colour bright green, slender, delicate 
looking plants. 
Stem — Simple or slightly branched. 
Leaves — Narrow, setaceous, spreading, upper ones slightly serrated near the apex ; nerve very broad, ceasing below the 
apex ; areolae narrow, oblong, bright green. 
Inflorescence — Synoicous. 
Barren Floiver (Antheridia) — Subcylindrical, paraphyses filiform, gemmiform. 
Fertile Floiver (Archegonia) — " With filiform paraphyses." 
Vaginula — Oblong. 
Capsule — Pendulous, pyriform, having a tapering neck, texture thin, bright orange colour, fruit stalk slender, 
same colour as the capsule. 
Calyptra — Small, cucullate. . 
Operculum — -Convex. 
Peristome — Double, with 16 outer teeth, reddish, transversely barred, having 16 inner teeth divided half way, 
alternate with the outer ones, pellucid. 
Annulus — "Distinct." 
Spores — Small, globular, greenish. 
General Habitat — Sandstone rocks, " frequently on garden pots" (Hooker). Fruit:— May and June. 
Species Illustrated — Leptobryum pyriforme (Wils.), Bryum pyriforme (Hedw.). 
Reference to Plate — a, Plant, natural size ; aa, Same, X 2-in. ; 6, Leaves, X 1-in.. ; c. Apex of leaf, X ?-in. ; d. Base of leaf, 
X 3-in. ; /, Capsule, X 2-in. ; ff, Teeth of peristome. 
This genus is represented in Britain by the species figured. 
