MUSCI. (MOSSES.) 667 



TRIBE XXXV. 



8O. HYPNTJIW, Dill. (Tab. 19.) 



Calyptra dimidiate, small, fugacious. Operculum between hemispherieal- 

 apiculate and conic-rostrate. Capsule ovate or cylindrical, more or less une- 

 qual, usually arcuate-cernuous. Peristome double ; the exterior 16 linear-lan- 

 ceolate articulate teeth, marked on the back by a medial line, and cristate on 

 the inner face by projecting cross-bars; the interior 16 carinate processes or 

 cilia, arising from a plicate membrane, with 1-3 ciliolae between each pair. 

 Inflorescence monoecious, dioecious, or polygamous. A genus, as generally 

 received, embracing a very large number of species, which, presenting in habit 

 and structure great diversity, may for the most part be combined into natural 

 groups, many of them seemingly of generic value. ^Yirvov, an ancient Greek 

 name for some sort of Moss.) 



1 1. THUlDIUM, Bryol. Europ. Stems profusely viUous, prostrate or ascend- 

 ing, 1 - 3-pinnat* ; brancfilets mostly short, slender, crowded : stem-leaves broadly 

 ovate, long-acuminate ; those of the branchlets much smaller, ovate, and ovate-lance- 

 olate ; all papillose ; areolation dot-like, granulated, opaque ; costa subcontinuous, 

 translucent: capsule oblong-oval, or cylindrical, more or less cernuous: operculum 

 heinispherical-apiculate or conic-rostrate. 



1. H. tamarlscimini, Hedw. Dioecious; stems prostrate ; ramification 

 closely 3-pinnate ; stem-leaves with reflexed and crenulate-denticulate margins ; 

 branch-leaves ovate-lanceolate ; perichaetial leaves fringed on the margin ; oper- 

 culum conic-rostrate. On the ground and old logs. A large and very com- 

 mon species. (Eu.) 



2. H. delicatllluni, L. Dioecious ; very much like the preceding, 

 but its ramification only 2-pinnate ; operculum conic, acuminate, not rostrate ; 

 perichaetial leaves not fringed On the ground, in dry places. Mountains of 

 Pennsylvania : rare. (Eu ) 



3. H. Hli Hilt II 1 11 ill, Hedw. Monoecious ; smaller than the preceding, 

 with a simply pinnate ramification ; capsule horizontal, oval, nearly regular ; 

 operculum large, convex-conic, with a long slender beak. On decayed logs, in 

 woods ; not rare. (Eu.) 



4. II. pyglil&Ulll, Bryol. Europ. (Muse. Bor.-Amer. Xo. 275.) Much 

 smaller than the last ; ramification 2-pinnate ; leaves more suddenly acuminated ; 

 perichffitial leaves elongated, with a more lax reticulation. Shaded ravines, on 

 limestone rocks, Central Ohio; gi'o wing with H. roinutissimuin. Among the 

 smallest of the Hypna. 



5. II. S i tu iis, Beauv. Monoecious ; intermediate in size between No. 



2 and 3 ; ramification pinnate ; easily recognized by its cylindrical, nearly regu- 

 lar, and erect capsule, with a conical, shortly rostrate operculum. Hilly dis- 

 tricts, on the base of trees, particularly the Beech. 



6. H. grr&cile, Br. & Sch. Monoecious ; size and ramification as in the 

 last; capsule oblong, mcurvcd-cernuous j operculum convex-conic, -ipiculate. 



