LEUCODONTACEAE. 491 



times obscurely toothed near the apex; base forming a long-decurrent wing to 

 the next lower leaf; basal cells oblong; upper cells hexagonal. Dioicous. Pedi- 

 cel erect or bent, about 15 mm. long; capsule nodding, about 2 mm. long, dark 

 red when mature, with a conspicuous swollen neck (like an acorn-cup or a 

 crown, hence the specific name) ; lid falling with the large annulus more or less 

 attached; peristome double; teeth brown; endostome pale, its segments split 

 along the keel, with 2-3 slender appendiculate cilia; spores small, green, ripe 

 in winter. 



In coppice, on dead wood and stones, New Providence, Abaco and Andros : 

 Florida ; West Indies ; South America ; also in Asia and Africa. COBONATB BRYUM. 



A doubtful species of Bryutn, was collected by L.. J. K. Brace at the quarry, 

 Nassau, New Providence, in February, 1918 (no. 9984) ; the specimens are sterile 

 and do not seem to agree with anything heretofore found. 



Family 8. LEUCODONTACEAE Broth. 

 LEUCODON FAMILY. 



Plants in dense mats or cushions, usually on trees. Stems creeping and 

 rooting, leafless or with rudimentary leaves at the apex of new stems; 

 branches pendent, simple or branching, usually with unequal and irregular 

 branchlets, seldom regularly pinnate or dendroid and circinate. Leaves 

 crowded, often imbricate when dry, spreading when moist, usually ovate, 

 acuminate, entire, or serrate at apex; vein single or double, sometimes 

 lacking-; cells smooth or rarely obscurely papillose or projecting at the 

 ends; base with several rows of alar cells, generally transversely elongated 

 or rounded and thickened. Dioicous or autoicous. Pedicels from lateral 

 buds with clasping bracts, short or elongate; capsule ovoid, sometimes 

 ribbed; calyptra cucullate, smooth or hairy; lid conic or beaked; annulus 

 usually present; peristome double, the outer of 16 short pale papillose, 

 bifid or perforate teeth; the endostome of a more or less developed mem- 

 brane with or without keeled segments and cilia. A small family of 9 

 genera and 69 species, widely distributed in temperate and subtropical 

 regions. 



1. LEUCODONTOPSIS Een. & Card. Bull. Soc. Bot. Belg. 32: 177. 1893. 



Plants slender and creeping on twigs or branches. Primary stems usually 

 closely attached to the bark, with short irregular spreading branches. Leaves 

 crowded, small, erect-appressed on the branches, spreading, longer and more 

 sharply pointed on the tips of the stems; lanceolate, acuminate, carinate and 

 plicate; margins revolute, entire or obscurely toothed at apex; vein single, 

 ending above the middle; upper cells long and narrow, with papillose project- 

 ing cells; alar cells round or quadrate and thickened, in several rows. Dioicous. 

 [Named in reference to its resemblance to Leucodon.~\ A small genus of only 

 three species, in all of which the fruit is unknown. Type species: Leucodontopsis 

 plicata Een. & Card. 



1. Leucodontopsis floridana (Aust.) E. G. Britton, Bryologist 15: 26. 1916. 



NecTcera (Pttotrichella?) floridana Aust. Bot. Gaz. 4: 152. 1879. 

 Leucodontopsis plicata Een. & Card. Bull. Soc. Bot. Belg. 32: 177. 1893. 

 Pilotrichella floridana Een. & Card. Eev. Bryol. 19: 11. 1893. 



Stems leafless except at the apical portions, there bearing small, ovate- 

 lanceolate, acuminate, ecostate, flat-bordered leaves; branches seldom more 



