412 BULLETIN OF THE BUREAU OF FISHERIES. 



KEY TO SPECIES. 



Trichomes 9 to 25 mic. in diameter, cells 2 to 4 mic. long; sheaths up to 5 mic. thick, color- 

 less, later becoming lamellose; apex not tapering, no calyptra, transverse walls usually 

 granulated i L. confervoides (p. 412). 



Trichomes 5 to 12 mic. in diameter, cells 2 to 3 mic. long; sheaths up to 3 mic. thick, colorless, 

 lamellose with age; apex slightly tapering, furnished with calyptra, transverse walls fre- 

 quently granulated 2. L. semiplena (p. 412). 



Trichomes 2.5 to 6 mic. in diameter, cells 1.5 to 5.5 mic. long; sheaths thin, colorless, later 

 becoming thick and lamellose ; apex not tapering, furnished with calyptra, transverse walls 

 usually not distinct 3. L. lutea (p. 413). 



1. Lyngbya confervoides Agardh, ex Gomont. 



Lyngbya confervoides, Agardh, 1824, p. 73. 



Lyngbya confervoides, Harvey, 1858, p. 103, pi. 470. 



Lyngbya nigrescens, Harvey. 1858, p. 102, pi. 4?d. 



Lyngbya luteo-fusca, Farlow, 1882, p. 35 (excluding synonyms). 



Lyngbya confervoides, Gomont, 1892, tome 16, p. 136, pi. 3,f .j-5. 



Lyngbya confervoides, Forti. in De Toni, 1907, p. 271. 



Lyngbya confervoides, Tilden, 1910, p. 119. pi. 5, f. 39. 



A. A. B. Ex. No. 48 (L. luteo-fusca). 



P. B.-A. Nos. 255, 1106. 



Plant mass abqut 5 cm. in height, forming extensive mats or an intricate ragged mass, fasciculate, 

 mucous; dull yellowish or dark green, sometimes violet when dry; filaments tangled, long, straight, 

 somewhat rigid, ascending from a decumbent base; sheaths up to 5 mic. thick, colorless, later becoming 

 lamellose and roughened on the surface; trichomes not attenuated at the apices, not constricted at the 

 joints, 9 to 25 mic. in diameter, cells 2 to 4 mic. long, apical cell rotund, no calyptra; transverse walls 

 usually granulated; cell contents olive or bjue-green. 



Maine to Florida; Nebraska; West Indies; warm and temperate waters everywhere. 



Very abundant on rocks and shells along town front, especially on Duncan breakwater, very abun- 

 dant on rocks of Fort Macon jetties, and less abundant on rocks of Shackleford jetty, Beaufort, N. C. 

 Forms the uppermost zone of algae occurring up to the median high-tide line, sometimes mixed with 

 minute specimens of Cladophora, Chaetomorpha, and Enteromorpha, sometimes forming pure growths 

 over large areas. April to October, probably throughout the year. This is the only species belong- 

 ing to the Myxophycese that has been found at Beaufort in sufficient quantity to be conspicuous. 



2. Lyngbya semiplena (Agardh) J. Agardh, ex Gomont. 



Calothriz semiplena, Agardh, 1827, p. 634. 



Lyngbya semiplena, ]. Agardh, 1842, p. n. 



Lyngbya semiplena, Gomont, 1892, tome 16, p. 138, pi. 3, f. 7-11. 



Lyngbya semiplena, Forti, in De Toni, 1907, p. 273. 



Lyngbya semiplena, Tilden, 1910, p. 118, pi. 5, f. 38. 



P. B.-A. Nos. 5, 1059, 1452. 



Plant mass rarely beyond 3 cm. in height, forming extensive mats, mucous; usually dull yellowish 

 or dark green, becoming dark violet when dry; filaments ascending from a decumbent tangled base, 

 soft, flexuous; sheaths up to 3 mic. thick, colorless, somewhat mucous, lamellose with age; trichomes 

 slightly attenuated at the apices, not constricted at the joints, 5 to 12 mic. in diameter, cells 2 to 3 mic. 

 long, apical cell bearing a depressed conical or rotund calyptra, transverse walls frequently granulated. 



Maine to North Carolina, probably farther; Nebraska; Washington; California; Mexico; West 

 Indies; Hawaii; Atlantic and Mediterranean shores of Europe. 



Very abundant, forming extensive mats almost covering posts of wharf and beacon between tide 

 lines, mixed with other Myxophyceas, Ocracoke, N. C. 



