50 CRTPTOGAMIA. 



14. Hypnum op^eodon, Sidliv. (Tab. 11.) 



H. dioicum, late ccespitans ; caulibus prostratis pinnatis ; foliis subfalcato- 

 secundis ovato-lanceolatis acuminatis semdatis ecostatis teimiter lineari- 

 areolatisy cellulis alaribus permagnis ; capsula oblonga subincequali 

 erecta abrupte brevicolla ; perist. dentilms lineali-lanceolatis feneatratis 

 ad latera simiato-dentatis ; operculo conico breviter rostrato. 



Hypnum opceodon, Sulliv. in Proceed. Araer. Acad. Art. Sci. (Jan. 1854.) 



Hab. Forest at the Eastern base of Mauna Kea, Hawaii, Sandwich 

 Islands. 



Stems rather short, prostrate, forming large dense golden yellow 

 shining mats. Ramification at right angles : main branches evenly 

 and closely pinnate, occasionally subbipinnate. Leaves crowded, 

 ovate-lanceolate, acuminate, serrulate, estriate, subfalcate-secund, eco- 

 state or obsoletely biscostate at base : texture membranous but firm, 

 composed of minute linear cellules, except at each of the basal angles, 

 where are three or four large, oblong, inflated, and yellowish. Peri- 

 chastium elongated; leaves numerous, ovate and oblong, sheathing, 

 ecostate, striate, produced into long, variously directed, and strongly 

 dentate points. Paraphyses abundant. Pedicel smooth, erect, flexu- 

 ose, slender, much twisted when dry, 11 to 2 inches long. Capsule 

 subcylindrical-oblong, erect, slightly curved on one side, with a sub- 

 globose collum not tapering into the pedicel, mouth oblique, exannu- 

 late. Operculum moderately rostrate from a conic base. Teeth of 

 the peristome linear-lanceolate with three or four large irregular open- 

 ings (hence the specific name) along the axis : the sides of the teeth 

 strongly and irregularly crenate-dentate : cilia lanceolate, carinate, 

 more or less ruptured along the keel ; the basal membrane rather nar- 

 row : ciliolse rudimentary. Sporules large. 



The general appearance of this species is strikingly similar to that 

 of Hypnum imponens, Hedw., but its peristome, operculum, collum of 

 the capsule, and areolation of the basal angles of the leaf, are quite 

 different. 



