80 
Note.—When unipapillate, bipapillate and pluripapillate are 
used in connection with leaf cells they mean respectively one, two, 
three or more papillae on each surface, unless otherwise stated ; 
when leaf cells are referred to they invariably mean those of the - 
stem leaves. ! indicates that the type has been seen by the author. 
Thuidium Br. and Sch. Br. Eu. fasc. 49-51. 1852 
Stem radiculose, creeping or ascending, erect, pinnately 
branched; branches simple, pinnate or bipinnate; stem and 
branches more or less thickly covered with simple or multiform 
paraphyllia; stem-leaves ovate-triangular to oblong-lanceolate, 
acuminate, cordate, plicate, strongly costate, papillate on one or 
both surfaces ; branch-leaves ovate, or ovate-lanceolate, acuminate. 
Monoicous or dioicous; perichetial bracts rather long, costate, 
plicate; capsule oblong-cylindrical, asymetrical, suberect, hori- 
zontal or pendulous; annulus compound; internal membrane fully 
one-third the length of the teeth; cilia two to four, usually well 
developed; operculum from short conical to long rostrate ; 
calyptra tubular-cucullate, long; spores small. 
Plants of unequal size growing in thin or thick mats on the 
ground, stones, rocks, rotten wood and on the base of trees. 
: Synopsis of the Species. 
Plants ascending-erect, 
Leaves rigid, cells quadrate-oblong; branch-leaves appressed when dry. 
7. abietinum. 
Leaves soft, cells oblong-linear ; branch-leaves crispate when dry. 
10. Blandowit. 
Plants creeping-ascending, 
Small; paraphyllia simple; branch-leaves appressed-incurved when dry, 
Branches papillate, capillary. 1. pygmarum. 
Branches not papillate. 2. minutulum. 
Large; paraphyllia multiform; branch-leaves appressed when dry, 
Stem-leaves spreading-recurved, margins plane; perichetium not ciliate. 
4. recognitum. 
Stem-leaves erect-spreading, margins recurved, 
Perichetium not ciliate; annulus narrow, indistinct, 
5. Philiberti. 
Perichetium ciliate ; annulus compound, distinct. 6. delicatulum. 
Medium sized; paraphyllia mostly linear- geniculate. 
Leaf-cells with several minute papillae. : 3. scitum. 
Leaf-cells with one, rarely two papillae. 
Leaves smooth or lightly papillate. I}. paludosum. 
Leaves strongly papillate on both surfaces. 
_ Branch-leaves roundish-ovate, short-acuminate. 8. Virginianum. 
Branch-leaves ovate-lanceolate, long-acuminate. 9. microphylium. 
