Naviculacea.] inftjsortal animalcules. 501 



coiymbose at the summit, acute ; na%-iculnD in very distinct rows, 

 small, lanceolate on one side ; on the other oblong and truncate. In 

 length l-1200th. Frond as much as 2 inches. 



ScHizoNEMA tricocej)IialHm. — Of a shining-green colour, very seta- 

 ceous, rigid, tufted, sparingly branched; inferior branches scattered, 

 simple ; terminal, aggregate, subulate, and curved ; uavicula) in very 

 close rows, small, broadly oblong and truncate. In length l-1440th. 

 Frond 1 inch. 



S. Bnjopsis. — Green, setaceous, rigid, branched ; upper branches 

 scattered, spreading, obtuse ; navicular larger, oblong ; on one side 

 rounded, on the other truncate. Length l-2000th to 1 -650th. 

 Size of frond 1 inch. 



S. Arhuscula = Kaunema arhuscula (Ehr.) — Green, or greenish- 

 yellow, very setaceous, rigid ; branches scattered, fasciculate, acute, 

 erect ; na\'iculDe very large, in rows ; on one side lanceolate-elliptic, 

 on the other broadly oblong and truncate. Length 1 -504th. Breadth 

 l-2160tli. Size of frond 2 inches. 



S. hydruoides. — Green or brownish, very setaceous, rigid, with 

 long branches and fasciculate ; secondary divisions capillary ; navi- 

 cula3 in rows, aggregated, small, but of greater proportional width ; 

 apices on one side round, on the other truncate. In length l-1380th. 

 Size of frond 2 to 3 inches. 



S. Smithii. — Arborescent, with a rather thick and almost simple 

 stem, but with a very branching apex, the branches being in dense 

 bundles; setaceous at the base, tapering upwards and capillary; 

 navicula) large, on one side lanceolate and somewhat obtuse ; on the 

 other, oblong and truncate. Length 1 -600th. Size of frond 2 

 inches. 



S. helmintosum. — Thick, much branched ; branches and branchlets 

 gradually tapering to acute ends; naviculae large, intertwined by 

 very delicate fibres ; their length three times their width ; on one 

 side sub-elliptic, with rounded ends ; on the other, ends truncate. 

 Length l-600th. Size of frond 2 to 3 inches. 



S. Scoparium. — Thick and branching ; branches dilate-d upwards, 

 cleft at the apex into very numerous capillary bimdles, or secondary 

 divisions; naviculie large, in a mesh- work of very delicate fibres ; 



