Musci. (mosses.) (33) 633 



spreading, entii'e, usually revolute on the margins, of a minute dot-like areola- 

 tion, except at the marginal base, the areolae there being larger, rectangular, and 

 pellucid. (Name from opdos, straight, and 6pi^, Tpix^s, a hair, in aUusion to the 

 straight hairs on the calyptra.) 

 § 1. Capsule immersed or slightly exserted. Moncecious {except in No. 5 and 6). 

 * Peristome single : cilia wanting. 



1. O. CUpillatum, HoiFm. Stems nearly 1' high; leaves lanceolate, 

 keeled; capsule immersed, with 16 striae; teeth of the peristome nearly equidis- 

 tant ; calyptra sparsely hairy ; male flower terminal. — On rocks, Niagara Ealls, 

 Drummond: Lake Superior, Agassiz. (Eu.) 



2. O. StsiriKlil, Hoppe & Hornsch. Very like the last species ; but its im- 

 mersed and obovate capsule is indistinctly 8-striated ; the male flower axillary. — 

 Texas, Wright. (Eu.) 



3. O. Eniomaluill, Hedw. Separated from the preceding (to which it 

 approaches closely) mainly by its exserted and distinctly 8-striated capsule. — 

 Kocks, near Salem, Mass., Lesquereux: Lake Superior, Agassiz. (Eu.) 



4. O. Texaunm, SuUiv. Larger than No. 2, which it resembles, but 

 its immersed capsule is oblong-pyriform and distinctly 8-striated ; teeth of the 

 peristome in pairs ; calyptra very haiiy ; leaves longer, narrower, and more re- 

 curved-spreading. — Texas, Wright : Santa Ee, New Mexico, Fendler. 



* * Peristome double. 



5. O. obttisifoliusn, Schrad. Stems 6" -10" high; leaves when moist 

 erect-patent, not recurved, ligulate from an oblong base, obtuse, concave, some- 

 what convolute on the margins, strongly papillose, the costa vanishing much 

 below the point ; capsule immersed, oblong-pyriform, the long apophysis gradu- 

 ally tapering into the veiy short pedicel ; cilia of the peristome 8, composed of 

 two rows of cellules half as wide as the teeth ; calyptra glabrous. — Trees, Cam- 

 bridge, Massachusetts, Lesquereux. (Eu.) 



6. ©. exfgT.tllMi, Sulliv. Nearly related to No. 5, but much smaller; 

 stems 3" -5" high; leaves more acute, scarcely papillose : costa stouter, extend- 

 ing to the point; the areola; at the base not so enlarged; capsule oval; the 

 apoj^hysis rather short ; pedicel longer ; cilia of the peristome 8, carinate, com- 

 posed of two rows of cellules fully as broad as the teeth ; operculum convex, 

 apiculate. — Base of trees, Santee Canal, South Carolina, Ravenel. — The small- 

 est of our Ortbotricha. — This and the related species have, scattered on the 

 surface of their leaves, a few articulated excrescences [Conferva Orthotriclii). 



7. O. Rdg^eri; Brid. Leaves spreading-recurved, when moist narrowly 

 ligulate from a ventiicose concave base, canaliculate, plane on the margins 

 above, revolute below, somewhat acute at the apex ; capsule and calyptra as in 

 No. 5; cilia 8, simple, filiform. — Trees, Lake Superior, Agassiz. (Eu.) 



8. ©. straugrulatum, Beauv. Stems short, compact ; leaves broadly 

 ovate-lanceolate, carinate, somewhat obtuse, the margins strongly reflexed ; cap- 

 sule oblong, somewhat pyriform, immersed, very much constricted below the 

 mouth when dry ; cilia of the peristome as in the last ; calyptra haiiy. — On 

 trees ; very common. 



