Cryphcea.] BRYACE^. 275 



7. D. Swartzii, Lindb. Ms. "With the habit of D. ca2nUa- 

 ceum, but more robust : upper leaves of the branches hooked, 

 the others variously secund, all densely crowded, obscurely three- 

 ranked, glossy, lanceolate at base, gradually narrowed into a 

 very long flat acumen, acutely serrate at the apex, distantly 

 denticulate below ; costa vanishing below the point : fruit 

 unknown. — Schimp. Syn. 461. Hypnum fluitans^ var. setra- 

 tum, Lindb. ; Hartm. Skand, FL, ed. 9, 18. If. exan7iulatum, 

 Guemb., vars. imnierswin and Cochlece., Austin, 1. c. 143. 



Hab. Pools of stagnant water, New Jersey (Axistin) ; California [Bo- 

 lander, Brewer). 



The species resembles Ihjpnum Jluitans, and has been considered by 

 Schijiiper as probably a variety of that species. It is distinct, however, 

 in the narrow cells of the leaves, the two basilar rows much longer and 

 somewhat broader, and in the denticulation entirely surrounding the leaf. 

 Tlie species is evidently dioecious. The male plants received from Cali- 

 fornia are covered with large polyphyllous flowers, with the perigonial 

 leaves broadly ovate, concave, and narrowed into a long slender flexuous 

 nearly entire point. 



Series III. PLEUROCARPI. 

 Fruit lateral by the position of the floAvers of both kinds, 

 placed in the axils of leaves, either upon the j^rimary stems or 

 upon branches. 



Teibe XXIX. NECKEREiE. 



Primary stems creeping, generally defoliate ; the secondary 

 erect or pendent, dichotomous or fasciculately or pinnately 

 ramulose. Leaves spreading, generally large, smooth, rarely 

 obscurely papillose, minutely areolate ; upper cells rhomboidal, 

 or short-linear in oblique rows, the lower long-linear, angular or 

 minutely quadrate. Fruit on perichjBtial branchlets without 

 rootlets at base. Calyptra conical or cucullate, naked or hairy. 

 Capsule generally immersed in the long imbricate perichretium, 

 erect, symmetrical, rarely curved. Peristome simj^le or double, 

 very rarely none. 



102. CRYPHJEA, Mohr. (PI. 5.) 

 Secondary stems more or less regularly pinnate or bipinnate. 

 Leaves spreading when moist, imbricate when dry, ovate, acu- 



