musci. (mosses.) 629 



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

 linear-lanceolate, more or less cloven and perforated. Inflorescence monoecious. 

 — Alpine species, growing upon moist rocks; stems densely caespitose, dichoto- 

 mously branched, with distichous and subulate-setaceous costate leaves, of an 

 areolation dense roundish above, enlarged diaphanous below. (Name from 

 Ston^o?, two-ranked, referring to the leaves.) 



1. I>. capilliacciim, Br. & Sch. Stems V-2' high; leaves abruptly 

 long-subulate from a dilated sheathing base, spreading, flexuose, the costa per- 

 current ; capsule subcylindrical, erect ; antheridia axillary, naked. — Northern 

 shore of Lake Superior, Agassiz. (Tab. 16.) (Eu.) 



2. I>. iuclinfitmii, Br. & Sch. Not so tall as the last; leaves more 

 crowded and narrower, the perichoetial ones 3-ranked ; capsule cemuous, oval ; 

 antheridia with perigonial leaves. — Northern shore of Lake Superior, Agas- 

 siz. (Eu.) 



24. EUSTICHIUM, Bryol. Europ. (Tab. 16.) 



1. E. Norvegicum, Bryol. Europ. Stems frond-like, flat, mostly sim- 

 ple (about 1' long and 1" broad), rooting only at the bulb-like base; leaves 2- 

 ranked, complicate, closely imbricating, erect; those on the middle of the stem 

 elongated-oblong, obliquely truncate, shortly acuminate, increasing in size as 

 they ascend ; the perichsetial leaves attenuated into a long and linear, flexuous, 

 pellucid, flat, equitant, and slightly serrulate point longer than the lamina ; are- 

 olation above subrotund, below oblong, that of the point of the perichsetial 

 leaves linear ; costa percurrent, its upper part narrowly winged : dioecious ; flow- 

 ers of both kinds terminal: fruit unknown. — Pendent on the perpendicular 

 faces of sandstone rocks, six miles south of Lancaster, Fairfield County, Ohio. 

 — The only other certain habitat recorded for this very interesting Moss is Ice- 

 land. That of Norway is apparently a mistake. — It is probably closely allied 

 to Eissidens. (Sulliv. in Mem. Amer. Acad. n. ser. 3. p. 57. 1. 1.) (Tab. 16.) 



Tribe IX. POTTIEjE. 



25. POTTIA, Ehrh. (Tab. 16.) 



Calyptra cuculliform. Operculum depressed-conic, more or less rostrate. 

 Capsule obovate-truncate or oval-oblong, exserted or immersed. Peristome 

 none. Inflorescence monoecious : male flower axillary. — Small annual or 

 biennial plants, growing on newly exposed soil, with entire ovate-oblong or 

 obovate-lanceolate and rather broadly costate leaves, of a quadrate or rectan- 

 gular areolation, enlarged at the base. (Named in memory of Professor J. F. 

 Pott, a German botanist.) 



1. P. truncnta, Br. & Sch. Stems 2" -4" high, gregarious, simple or 

 branched ; leaves obovate-lanceolate, mucronate by the excurrent costa; capsule 

 obovate, truncate; operculum obliquely rostrate. — (P. eustoma, Ehrh. Gym- 

 nostomum truneatulum, Hedw.) — On the ground, New England and Pennsyl- 

 vania. (Tab. 16.) (Eu.) 



53* 



