324 BRYACEJE. [HT/pnum. 



10. H. gracile, Bruch & Schimp. Much like JI. scitum, 

 differing in the stems more diffusely divided, the leaves longer 

 acuminate, dentate-serrate above, the capsule short-necked, 

 turgid, oval-oblong, cernuous or nearly horizontal with a broad 

 orifice, the short conical or mamillate lid, and the segments 

 separated by three long cilia. — Lond. Journ. Bot. ii. 668 

 (1843) ; Sulliv. Muse. Allegh. n. 5, and Icon. Muse. 156, t. 100. 

 IT. microjj/ii/lhcm, Muhl. Cat. Thuidium gracile^ Bruch & 

 Schimp. 1. c. 5 ; Lindb. Faun. Flor. Fenn. ix. 268. 



Var. Lancastriense, Sulliv. &> Lesq. Leaves shorter, 

 appressed, more distinctly serrate at the apex ; perichretium 

 greenish : capsule smaller and narrower ; operculum longer. — 

 Muse. Bor.-Amer. Exsicc. n. 278. 



"Var. Ravenellii, Sulliv. & Lesq. 1. c, n. 279. Plants 

 smaller, slender : leaves flat on the borders, with dense areola- 

 tion : pedicel shorter, curved ; cilia appendiculate ; lid longer. 



Hab. On decayed logs in woods; the first variety in less humid situa- 

 tions, on roots of trees in dry hilly regions; the second on stone, brick 

 walls, etc. South Carolina and Florida. 



This species is extremely variable according to its location. II. pallens, 

 Lindb. Ms. (Schimp. Syn. ed. 2, Gil), differs from the normal form of 

 H. gracile n:\erely in the narrower and longer-pointed leaves, those of the 

 branchlets more papillose and sharply serrate at the apex. //. varium, in 

 Drummond's second collection (n. 140, 141), found near St. Louis, is inter- 

 mediate between this form and the typical one, and distinct from both 

 in its nearly smooth leaves. H. Virginiamim, Brid. Bryol. Univ. ii. 576 

 (Dill. Muse. 282, t. 36, fig. 18. Thuidium Virginianum, Lindb. Muse. 

 Scand. 36), is recognized by Lindberg as identical with the var. Lan- 

 castriense. 



11. H. calyptratum, Sulliv. Plants very small; stems 

 creeping, filiform, simply pinnate, flagelliform at the apex : 

 leaves open-erect, broadly ovate, narrowly long-acuminate, 

 denticulate to the middle ; borders recurved toward the base ; 

 costa percurrent : areolation minute, subquadrate : caly2:>tra very 

 long, cuculliform, descending below the base of the capsule, 

 persistent : capsule long-pedicelled, cylindrical, oblique, slightly 

 curved ; operculum conical, obtuse ; segments cleft between the 

 articidations, separated by single short cilia ; annulus none. — 

 Pacif. R. Rep. iv. 190, t. 10. 



Hab. Near Los Angeles, California, on the ground [Bigelow). 



The long calyptra, the absence of the annulus, and the segments cleft 

 and separated by solitary cilia, especially separate this species from the 

 preceding. 



