HYPNACEAE. 497 



apiculate; calyptra cueullate; peristome double. [Greek, referring to the sym- 

 metric leaves.] A genus of 168 species, mostly American, in temperate and 

 tropical regions. Type species: Isopterygium planissimum Mitt. 



1. Isopterygium micans (Sw.) Cardot, Bull. Herb. Boiss. 4: 10. 1896. 



Eypnum micans Sw. Adnot. Bot. 175. 1829. 



Plants growing in dense, glossy, yellowish-green mats. Stems slender, 

 decumbent; branches simple or divided; leaves crowded, spreading, small, 0.85 

 mm. long by 0.25 mm. wide, ovate, acuminate, faintly serrate; veins short, 

 double, obscure; cells 10 to 15 times longer than wide, a few at basal angles 

 distinctly shorter and broader. Pedicel erect, slender, up to 1 cm. long; cap- 

 sule horizontal, curved, contracted below the mouth when dry, about 1 mm. 

 long; lid conic, slightly apiculate; cilia more or less developed; spores small. 



On roots of palms and rotten wood in coppices, New Providence, Great Bahama 

 and Abaco: — United States; Bermuda; Cuba; Jamaica. Glossy Isopterygium. 



3. VESICULARIA C. Muell. Flora 82: 467. 1896. 



[HoMALiA Section Vesicularia C. Muell. Syn. 2: 233. 1851.] 



Plants growing in moist shady places, forming thin mats on the ground. 

 Stems creeping; branches irregularly pinnate, usually short; leaves not 

 crowded, shrunken and twisted when dry, usually flattened and of two kinds, 

 the lateral ones larger and unequal, or falcate^ the upper and lower ones more 

 regular and much narrower, often longer and more acuminate; veins two, short 

 or none; margins often bordered, entire or serrate; cells large and hexagonal, 

 smooth, the alar not enlarged. Autoicous. Pedicels exserted and slender; cap- 

 sules horizontal or nodding, ovoid and contracted below the mouth when dry; 

 annulus present; peristome double; lid flat and beaked; calyptra cueullate; 

 spores small. About ninety species have been described, many with very ob- 

 scure and minute differences. [Named in reference to the large leaf-cells.] 

 Type species: HooTceria Meyeniana Hampe. 



1. Vesicularia vesicularis (Schwaegr.) Broth. Pflf. 232-233: 1094. 1908. 



Eypnum vesicidare Schwaegr. Supp. 2-: 167, pi. 199. 1827. 



Plants pale or yellowish green. Stems slender and rooting with short ir- 

 regular branches; stem-leaves with long recurved tips up to 1 mm. long, about 

 three times longer than broad; branch-leaves of two kinds, the lateral unsym- 

 metric, shorter and less acuminate^ up to 0.85 mm. and only about twice longer 

 than broad with the cells about twice as long as wide ; the upper and lower ones 

 longer and narrower, with cells about five times longer than broad; leaves all 

 ecostate or faintly bicostate, the margins bordered by one row of narrow cells, 

 either entire or minutely toothed at apex; perichaetial leaves suddenly con- 

 tracted to a slender recurved, entire or serrulate tip. Autoicous. Pedicel 

 slender, 1.5-2 cm. long; capsule nodding, 1-1.5 mm., ovoid, with a distinct 

 neck; walls of swollen inflated cells; lid conic-beaked; annulus large; peristome 

 with a red base, teeth yellow, pale and papillose at apex, lamellate on the in- 

 side; endostome brown, the keeled segments split and papillose; spores small, 

 ripe in winter. 



On branches and roots of trees in coppices and in sink-holes, New Providence, 

 Eleuthera and Andros : — Florida ; West Indies and South America. Vesicularia. 



