JUNGERMANNIACE.E. (SCALE-MOSSES.) 709 



apex decurved, more or less denticulate ; lower lobe oblong, obtuse, with an 

 acute tooth at base, longer but narrower than the quadrate underleaves, both 

 with strongly recurved sparsely denticulate margins. (Madotheca Thuja, Du~ 

 mart.) On rocks and trees; more common westward. (Eu.) 



4. P. dentata, Lindb. Mostly fuscous-green, irregularly pinnate or sub- 

 dichotomous ; leaves more remote on the branches, obliquely round-ovate, the 

 rounded summit slightly decurved, more or less denticulate ; lower lobe de- 

 curreut, twisted, obliquely ovate, acute, with recurved undulate denticulate 

 margin and a large acute tooth at base ; underleaves twice as wide as the 

 lower lobes, quadrate-oval, the undulate reflexed margin dentate, especially 

 near the base. (Madotheca rivularis, Nees.) Shaded rocks, Yellow Springs, 

 Ohio (Sullivant). (Eu.) 



5. P. Sullivantii, Underw. Stems strongly decurved at the ends in 

 drying ; leaves suberect, the straight ventral margin strongly involute toward 

 the apex ; cells large, punctate-stelliform ; perianth broadly keeled beneath, 

 the keel 2-augled. (Madotheca Sullivantii, Aust.) Alleghany Mts. (Sulli- 

 vant) ; rare. 



6. PTILIDIUM, Nees. (PI. 24.) 



Leaves incubous, complicate-bilobed, each lobe divided and lacerately cili- 

 ate ; underleaves 4 - 5-lobed, ciliate. Dioecious. Fruit terminating short 

 branches. luvolucral leaves 2-4, 4-cleft ; perianth terete, obovate, the mouth 

 connivent, plicate, denticulate. Calyptra pyriform, coriaceous. Capsule ovate. 

 Spores globose. Antheridia in the base of closely imbricated leaves. (Name 

 a diminutive of irriKov, a feather, from the fringed foliage.) 



1. P. ciliare, Nees. Stems crowded, subpiunate ; fringes of the foliage 

 long-setaceous. (Blepharozia ciliaris, Dumort.) On rotten logs and stumps ; 

 common. (Eu.) 



7. TRICHOCOLEA, Dumort. (PI. 24.) 



Leaves succubous, 4 - 5-divided, and with the underleaves setaceously 

 fringed. Dioecious. Fruit terminal, or axillary from the growth of inno- 

 vations. Involucral leaves coalescent into an oblong truncate hairy tube, 

 blended in our species with the calyptra ; perianth none. Capsule oblong, its 

 pedicel bulbous at base. Elaters free. Antheridia large, in the axils of leaves 

 on terminal branches. (Name from 6pi, hair, and /coAeos, a sheath, from the 

 hairy involucre.) 



1. T. toment611a, Dumort. Stems pinnately decompound, densely 

 tufted, glaucous, 2-6' long ; leaves nearly uniform ; underleaves subquadrate, 

 as wide as the stem. Among mosses in swamps; common. (Eu.) 



T. Bim>LEc6Mi/E, Aust., very imperfect!}' described from specimens col- 

 lected in Urbana, Ohio, is said to be simply and rather distantly pinnate. 



8. HERBERT A, S. F. Gray. (PI. 24.) 



Leaves large, incubous or nearly transverse, narrow, 3-ranked, the under- 

 leaves being scarcely smaller, cleft to or below the middle, the lobes acute. 

 Dioscious. Fruit terminal on a long branch. Involucral leaves numerous, 

 equitant ; perianth ovate-subulate or narrowly fusiform, 3-angled, deeply 6-8- 



