100 CRYPTOGAMIA. 



an oblique, upwardly directed acuminulation, strongly serrate at apex, 

 with a narrow, pellucid margin, costa simple, cellules minute, rhom- 

 boid, subopaque, their primordial utricles conspicuous. The stipuli- 

 form leaves one-fourth the size of the main leaves, and thrice the 

 width of the stem, rotund-ovate, cuspidate, slightly serrate, narrowly 

 margined, their costa distinct and continuous. Capsule horizontal, 

 oval, tapering gradually into a distinct collum. Operculum conico- 

 cupulate, with a decurved rostrum, nearly as long as the capsule. 

 Peristome hypnoid, large, pale yellow; ciliolse in pairs. Calyptra 

 minute, narrowly conic, split on one side, scarcely covering the 

 rostrum. Pedicels 4-7 lines long, erect, not aggregated, red, rather 

 thick, easily separating from the vaginula, the upper portion of which 

 is not hidden by the loose, lanceolate, long-acuminate, subecostate, 

 perichsetial leaves. Monoicous : antheridia 7-9, large, linear, long- 

 pedicelled ; paraphyses small, scarcely longer than the pedicel of the 

 antheridia, composed of 6-9 cellules, the upper one about three times 

 as long as all th^ rest together. 



H. incrassato-limbatum, and H. nivale (Mull. Synop. 2, p. 8, 9), are 

 nearly allied to our species ; the first, however, is dioicous, and has a 

 thickened and broader margin to the leaf; the second has the costa of 

 its stem-leaves constantly bifurcate, and its stipuliform leaves serni- 

 costate, but gives, like H. Brasiliense, to water in which it is immersed, 

 a yellow color. 



If. scutellatum, Tayl., another closely related species, has shorter 

 and thicker pedicels, and semi-costate stipuliform leaves, and does not 

 color water yellow. 



The "spicules breves fragiles" noticed in Lond. Jour. Bot. 6, p. 338, 

 as being on the sides of the stems of H. scutellatum, are compact, cuspi- 

 date, undeveloped branch-buds, composed of three or four minute, 

 linear-lanceolate leaflets; they occur on H. Brasiliense, and other 

 South American species, and are altogether different from the setulge 

 of H. tamariscinum, Hedw. 



Plate 26, B. — Hypopterygium Brasiliense : plants, of the natural 

 size. Fig. 1. Portion of stem, with main and stipuliform leaves, male 



