88 A MANUAL OF MOSSES 



immediate region, but likely overlooked on account of small 

 size. 



Family V. TORTULACBAB. 



Autoicous or dioicous, rarely par-, syn-, or polyoicous: 

 mostly small or medium-sized, more or less densely cespitose, 

 rarely gregarious : stems mostly with central strand, radiculose 

 below, thickly foliate, simple or more or less branched ; leaves 

 pluri-seriate, rarely 3-seriate, lanceolate to broadly ovate or 

 obovate ; costa heterogeneous, mostly percurrent, or excurrent, 

 sometimes with longitudinal lamellae or with green branched 

 filaments on the ventr.al surface above the middle; leaf-cells 

 parenchymatous, the basal rectangular to elongate, mostly 

 pellucid, or hyaline, upper cells always chlorophyllose, on both 

 sides mostly warty papillose, loose, sometimes towards the 

 apex 4-6-angled, or small and rounded-quadrate ; seta more 

 or less elongate, mostly straight, rarely almost lacking ; capsule 

 erect, symmetric, rarely slightly inclined, straight to slightly 

 arcuate, mostly oblong to cylindric, rarely oval to spherical ; 

 coUum short, rarely none; peristome various to none, mostly 

 inserted on the mouth of the urn, usually without projecting 

 trabecule; teeth 16, straight or spirally twisted, often united 

 at base into a tube, entire or 2-3-cleft into filiform-subulate 

 divisions, papillose ; operculum mostly conic, rostrate ; calyptra 

 mostly cucuUate, smooth, rarely papillose or minutely bristly 

 or short-hirsute. 



A very large family, mainly confined to the temperate 

 zones, occurring almost entirely on soil or on rocks. The 

 systematic relationships and the scope of the family are vari- 

 ously treated by different bryologists who have taken dif- 

 ferent characters as the basis for the various classifications. 



Key to Genera. 



a. Leaves mostly narrow, often linear-lanceolate, never broadest 

 above the middle; costa with several guides, no accompanying 

 cells, but 2 stereid bands, rarely long-excurrent. 



b. 

 a. Leaves mostly broad, ovate-oblong to spatulate or lingulate; costa 

 with 2 median guides, with accompanying cells, and 1 stereid band, 

 mostly more or less long-excurrent. 1. 



b. Plants minute; areolation dense, strongly papillose above: 



capsules cleistocarpous. i. Astomum. 



b. With deciduous operculum. c. 



c. Peristome none. d. 



c. Peristome present, rudimentary or well-developed. 



e. 

 d. Operculum deciduous with the columella detached. 



4. Hymenostylium. 

 d. Columella remaining in the urn after the falling away of the 

 operculum. 3. Gymnostomum. 



e. The exterior surface of the teeth more strongly developed and 

 with projecting plates. 2. IVeisia. 



