628 musci. (mosses.) 



21. DESMATODOK, Brid. (Tab. 16.) 



Calyptra cuculliform. Operculum conic, obtusely rostrate. Capsule oval- 

 oblong or cylindrical, annulate, long-pedicellate. Peristome single : teeth 16, 

 subulate. 2 - 3-cleft, united by a basilar membrane. Inflorescence monoecious 

 or dioecious. — Plants of rather low stature, growing on the ground or on rocks, 

 in general habit, ramification, and structure of leaves having much in common 

 with Triehostomum and Barbula. — (Name from Seo-fia, -aros, a bam], mid oduv, 

 a tooth, in allusion to the membrane uniting the teeth.) 



1. I>. arenfgceiss, Sulliv. & Lesqx. (Muse. Bor.-Amer., No. 93.) 

 Stems 2" -3" high, gregarious ; leaves oblong, lingureform, very obtuse, slightly 

 denticulate at the apex ; apiculate by the excurrent costa ; capsule cylindrical, 

 tapering into the pedicel (4"- 5" long) ; annulus simple, persistent; teeth of the 

 peristome 2-cleft, straight, white. — Sandstone rocks, Ohio. —Near D. flavicans. 



2. I*. pBimtlhtdbms, Sulliv. & Lesqx. (Muse. Bor.-Amer., No. 94.) 

 Stems 2" - 5" high, fastigiately branched ; leaves erect, elongated-oblong, very 

 obtuse, carinate-concave, narrowly reflexed on the margins ; areolation minute, 

 opaque, dot-like above, larger oblong and pellucid below ; costa excurrent into 

 a smooth white hair-point nearly as long as the leaf; capsule elliptic-cylindrical, 

 its mouth orange-red ; operculum £ the length of the capsule ; teeth of the peri- 

 stome pale yellow, more or less cloven along the medial line ; annulus large : 

 dioecious. (Barbula muralis, James ; not of Hedw.) — Grows in hoary or pale- 

 green and dense patches, on brick pavements, Charleston, S. Carolina, Bavenel: 

 on the walls of the College at Nashville, Tennessee, Lesquereux. (Tab. 16.) 



22. DIDYMODOS, Br. & Sch. (Tab. 16.) 



Calyptra cuculliform. Operculum conic, shortly and obtusely rostrate. Cap- 

 sule subcylindrical, annulate, long-pedicellate. Peristome single : teeth 16, 

 linear-lanceolate, entire, or more or less bifid, rather short, fugacious, and with- 

 out a basilar membrane. Inflorescence various. — Very nearly allied to the last 

 genus ; and it is questionable if either is entitled to rank higher than as a section 

 of Triehostomum. (Name from bi^vfj-os, twin, and 68a>i> y a tooth.) (Tab. 16.) 



1. D. 1'iatoellsis, Br. & Sch. Stems £'-1' high, loosely ea?spitose; leaves 

 spreading, oblong-lanceolate, recurved on the margins, costate to the apex, the 

 upper ones dull-green, the lower reddish ; annulus simple ; antheridia naked in 

 the axils of the perichsetial leaves. — Pennsylvania, on the ground; rare. 

 (Tab. 16.) (Eu.) 



2. I>. luridus, Hornsch. Rather smaller than the last; leaves lurid- 

 green, rigid, ovate-lanceolate, with a reddish-brown costa, ceasing at the apex ; 

 peristome minute, irregular ; male flower terminal on a separate plant. — Falls 

 of Niagara, Drummond. (Eu.) 



Tribe VIII. DISTICHIE.E. 



23. DISTICHIUITI, Br. & Sch. (Tab 16.) 

 Calyptra cuculliform, long-rostrate. Operculum conic, short. Capsule oval- 



