102 
OSCILLATORIACEHS. 
2. Lyngbya ferruginea , Ag. ; filaments slender, flaccid, curved, forming a thin stratum 
of a verdigris green colour, which gradually changes to a pale chestnut (but resumes 
the green in drying). Ag. Syst. p. 73. Harv. Phyc. Brit. tab. 311. L. ceruginosa, 
Kutz. Sp. Alg. p. 282. (Tab. XLVII. B.) 
Hab. On muddy shores, in tide pools and floating in ditches of salt or brackish water 
near the sea. Haarlem River, N.Y. close to the High Bridge, W. H. H. Salt ditches 
at Hoboken and near Green Port, Professor Bailey, (v. v.) 
Stratum thin, expanded, covering the mud to an indefinite extent, or floating on the 
surface of stagnant salt water, generally of an intense verdigris or blueish green colour, 
now and then foxy or rust colour, scarcely at all gelatinous. Filaments about ‘001 of 
an inch in diameter, flaccid, slightly flexuous, rather tough, with very thin, membranous 
cell-walls, filled with dense closely and strongly annulated, bluish-green endochrome, 
occasionally with empty spaces. The striae are very evident. In the dry state the blue- 
green colour is mostly preserved ; and the surface is not glossy. 
Plate XLYII. B. Fig. 1. Portion of the stratum of Lyngbya ferruginea. Fig. 2. 
Portion of a filament, magnified. Fig. 3. Section of the same, more highly magnified. 
3. Lyngbya fulva , Harv. ; filaments slender, elongate, flexuous, fulvous, issuing in 
erect, crisped, plumose fascicles from a dark coloured stratum ; cell- wall thick, forming 
a broad limbus to the endochrome. (Tab. XLYII. F.) 
Hab. On the granite masses composing the breakwater at Stonington, Conn. Professor 
Bailey, (v. s. in Herb. T.C.D.) 
Stratum attached to the rock, dull olivaceous, throwing up long fascicles of filaments, 
an inch or more in length, and standing upright in the water. Filaments about the 
size of those of L. ferruginea , but with very thick walls, which form a glassy sheath to 
the enclosed fulvous or ochre coloured endochrome ; the hyaline border being nearly half 
as wide as the coloured portion. The annuli are strongly marked and very closely set. 
This somewhat resembles L. luteofusca , Ag., but the walls of the tube are much 
thicker, as thick in proportion to the enclosed matter as are those of L. majuscula to 
the matter in its tube. 
Plate. XLYII. F. Fig. 1. Lyngbya fulva , the natural size. Fig. 3. Portion of a 
filament, magnified. Fig. 2. Section of a filament, more highly magnified. 
4. Lyngbya nigrescens , Harv. ; filaments very slender, flaccid, densely interwoven 
into a fleecy, blackish-green stratum. (Tab. XLYII. I).) 
Hab. Sea shores or mud, &c. Canarsic Bay, Long Island, Mr. Hooper. Peconic 
Bay. W. H. H. Also on leaves of Zostera, Peconic Bay, Mr. Hooper. 
