Myxophyceae 259 



ner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 197. 1903. 

 Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223, 

 243. 1905. Borgesen and Jonsson. The Distribution of the Marine Algae 

 ci the Arctic Sea and of the Northernmost Part of the Atlantic. Bot. 

 Faeroes. App. XXV. 1905. 



Plate XVI. fig. II, 12. 



Plant mass caespitose, velvety, widely expanded, dark green or olive; 

 filaments 10-18 mic. in diameter, up to i mm. in length, twisted and curled, 

 moderately thickened at the base; sheaths somewhat thick, colorless, yel- 

 lowish brown, or forming yellowish and colorless zones, lamellose in the 

 larger filaments, variously dilated and expanded; trichomes 8-15 mic. in 

 diameter, ending in a hair; heterocysts one to three, basal; hormogones 

 numerous in the sheath, four or five times longer than their diameter. 



Greenland. Forming "in conjunction with several other algae, a thin 

 stratum over stones within the upper part of the littoral zone. It is scarce 

 here (in the Polar Sea), and nowhere occurs in great masses. It has been 

 found both on exposed and sheltered coasts." Greenland Sea; West coast 

 of Spitzbergen. (Kjellman). Forming a gelatinous cushion upon rocks in 

 the littoral region. (Sorenson). East and west portions. (Borgesen and 

 Jonsson). Newfoundland. On rocks between tides. Quidi Vidi. July 1897. 

 (Holden). Maine. Very common on rocks. Seal Harbor; Little Cran- 

 berry Isle (Collins); Sea Wall (Holden). New Hampshire. (Collins). 

 Massachusetts. On rocks near high water mark. Marblehead. June 1901. 

 (Collins). Rhode Island. Rocks near high water mark. (Bailey and Ol- 

 ney.) Connecticut. On rocks. Stratford Shoals. July, September. (Hol- 

 den). New York. Shores of Long Island. Greenport, Little Egg Harbor. 

 Summer. (Pike). Statin Island. (Pike). New Jersey. Hoboken, Beesleys 

 Point. (Pike). On wharves. Atlantic City. (Morse, Martindale). On wood- 

 work. (Morse). New Jersey. Marine. Hudson: Hoboken; Cape May, 

 Beesley's Point. (Pike). On wharves, Atlantic City. (Morse). Washing- 

 ton. In salt water. Puget Sound. (Saunders). 



467. Calothrix contarenii (Zanardini) Bornet and Flahault. Revis. des Nos- 

 toc. Ann. Sci. Nat. Bot. VII. 3: 355- 1886. De Toni. Syll. Algar. 

 S: 610. 1907. 

 Collins. Notes on New England Marine Algae. V. Bull. Torr. Bot. Club. 

 18: 336. 1891; The Algae of Jamaica. Proc. Am. Acad. 37: 241. 1901. Col- 

 lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23. no. 11 13. 1903. 



Plate XVI. fig. 13- 



Plant mass crustaceous, compact, orbicular, smooth, glistening, black- 

 ish green; filaments 9-1S mic. in diameter, up to i mm. in length, very 

 densely crowded, parallel, erect, moderately fiexuous; decumbent and thick- 

 ened at the base; sheaths somewhat thick, colorless or yellowish, dilated 

 into lamellose, funnel-shaped expansions; trichomes 6-8 mic. in diameter, 

 ending in a slender long hair; cells equal to or shorter than their diameter; 

 heterocysts, one to two, basal. 



