FRESHWATER ALGAl. 51 
Genus Navicuta Bory. 
80. NAVICULA MUTICOPSIFORMIS. 
Navicula muticopsiforme W. and G. 8. West, op. cit., p. 284, Pl. XXVL., fig. 
_ 
SY) 
_ 
Long. valvy. = 12°5 w; lat. valv. = 5°5 p. 
Hab.—Freshwater pond, Granite Harbour, January 20th, 1902 (rather rare). 
81. NAVICULA SEMINULUM. 
(PST uhics: 97, 98.) 
Navicula Seminulum Grun., Verhandl. k.k. zool.-bot. Ges., Wien (1860), p. 552, Tab. IL, fig. 2; Van 
Heurck, Synops. Diat. Belg. (1880-85), p. 107, Pl. XIV., fig. 9. 
Long. valv. = 16-20 p; lat. valv. = 4°5-5 p. 
Hab.—On ice, four feet above frozen watercourse through “ Penknife ice,” MeMurdo 
Bay, September 13th, 1902; pond in ice, off Black Island, McMurdo Strait, December 
31st, 1902; in freshwater ice under boulder, Cape Adare, January 9th, 1902. 
The valves of this fairly common form were obviously swollen in the middle, and 
very gradually tapered from there towards the two ends, which were occasionally very 
faintly capitate. The strize were in many cases a little further apart in the middle of 
the valve than elsewhere, in which respect the specimens approached N. minima Grun., 
but the shape of the valve in this species is rather different. 
82. NAVICULA MUTICOPSIS. 
Navicula muticopsis Van Heurck, Diatomées, Résult. d. voyage du 8.Y. ‘ Belgica’ (1909), p. 12, Pl. IL., 
fig. 181. 
Long. valv. = 13-25 p; lat. = 7-9 p. 
TTlab.—Pond, Cape Adare, January 9th, 1902; on ice, McMurdo Bay, September 
13th, 1902; pond in ice, off Black Island, McMurdo Strait, December 31st, 1902; 
Gap pond, Winter Harbour ; freshwater pond, Granite Harbour; pond in eskers upon 
ice, half-way between Black and Brown Islands, January 8rd, 1903; in ice, under 
boulder, Cape Adare, January 9th, 1902. 
This is certainly one of the most widely distributed of Antarctic Diatoms. Both 
of the forms recorded by Messrs. West (op. cit., pp. 283-284) were of wide occurrence. 
83. NavICULA CYMATOPLEURUS. 
(PELL, fig. 1On:) 
Navicula cymatopleura W. and G. 8. West, op. cit., p. 285, Pl. XXVL., figs. 188, 134. 
Long. valv. = 24-30 p; lat. valv. = 4-5°5 p. 
Hlab,—On ice, four feet above frozen watercourse, through ‘“ Penknife ice,” 
