THE MARINE ALG.E OF NEW ENGLAND. 35 



Gloucester, Mass., Mrs. A. L. Davis, and southward ; Europe, Sum- 

 mer. 



A common species of the New England coast, abundant in shallow, brackish pools, 

 where it covers the exposed algas and Zostera. Much less striking than L. majuscula, 

 Harv., from which it is distinguished at sight by its brighter green color, changing to 

 yellowish rather than blackish, by, the diameter of its filaments, which is about half 

 that of L. majuscula, by its thinner sheath, and by forming thin strata rather than 

 loose tufts. In the Ner. Am. Bor., Part III, the diameter of -the filaments of L. majus- 

 cula, Harv., is given as .05 inch, and that of the filaments of L. ferruginea, Ag., as .001 

 inch, which is evidently incorrect, as one species is not fifty or even five times larger 

 than the other. 



L. luteo-fttsca, Ag. (L. fulva, Harv., Ner. Am. Bor., Part III, 

 p. 102, PI. 47/.) 



Filaments fasciculate, erect, greenish yellow, .008-10 mm in diameter, 

 sheath distinct. 



Exs. — Alg. Am. Bor., Farlow, Anderson & Eaton, No. 48. 



Stonington, Conn., Bailey; Noank, Conn. ; Wood's Holl, Mass., W. G. 

 F.; Europe. 



Apparently a common alga of Southern New England, differing in its habit from all 

 our other species of the genus, except L. tenerrima. It grows in large patches on 

 stones and wood-work between tide-marks. The filaments are erect, from one to three 

 inches high or somewhat higher, when in their best condition olive-colored, but 

 more frequently a pale yellow. The thickness of the sheath, by which Harvey sepa- 

 rated his L. fulva from L. lutw-fusca, Ag., is by no means constant, and the species 

 cannot be kept distinct. As is the case in several of the species of Lyngbya, the sheath 

 is sometimes two, three, or even a greater number of times thicker than at others. 



L. tenerrima, Thuret, mscr. 



Filaments slender, fasciculate, erect, bluish green, .0035 mm in diam- 

 eter, sheaths very thin. 



Gloucester, Mass., Mrs. A. L. Davis; Newport, R. I.; Europe. 



This species was first detected near Gloucester, by Mrs. Davis, growing apparently 

 on sand-covered rocks. The filaments are bluish green, and not over a quarter of an 

 inch high. The species will be easily recognized by the diameter of the filaments, 

 which is decidedly less than that of any other of our species. Dr. Bornet, to whom 

 a specimen was sent, considers our plant the same as that collected by the late M. 

 Thuret, at Biarritz, France, and named by him L. tenerrima. I have since found it in 

 considerable quantity at the base of the cliffs near the Winans mansion, at Newport. 



L. nigrescens, Harv., Ner. Am. Bor., Part III, p. 102, PI. 47 d. 



" Filaments very slender, flaccid, densely interwoven into a fleecy, 

 blackish-green stratum." (Harvey, 1. c.) 



Canarsic Bay, L. I., Hooper; Peconic Bay, Harvey ; on mud and on 

 Zostera, Gloucester, Mass., 2Irs. A. L. Davis. 



Var. major. 



Filaments forming a dark-brown gelatinous stratum, .0152 mm in diam- 

 eter, sheath thin. 



