48 F. E. FRITSCH. 



FRAGILARIACE^E. 



Genus FRAGILARIA Lyngb. 



72. FRAGILARIA CURTA. 



(PI. III., fig. 147.) 



Fragilaria curta Van Heurck, Result, du voyage du 8.Y. ' Belgica,' Bot., Diatomees (190'J), p. 24, PI. III., 

 fig. 37. 



Long. valv. = 1 9 /A ; lat. valv. = 6 p.. 



Hob. Pond some distance behind hut, Cape Adare, January 9th, 1902 (isolated). 



The specimens agreed in all respects with Van Heurck's description and figure. 

 The valve is very slightly wider at one end than at the other. The striae are 

 interrupted in their transverse course by a scarcely perceptible division, the last three 

 or four "at each end being curved. 



73. ? FRAGILARIA LINEARIS. 

 Fragilaria linear is Castracane, ' Chall.' Rep., Diatom. (1886), p. 56, PI. XXV., fig. 12. 



Long. valv. = 38/a, ; lat. valv. = 6' 5 p.. 



Ilab. Pond some distance behind hut, Cape Adare, January 9th, 1902 (isolated). 



74. FRAGILARIA OBLIQUECOSTATA. 

 Fragilaria obliquecostata Van Heurck, op. cit., p. 25, PL III., fig. 38. 



Hob. Pond some distance behind hut, Cape Adare, January 9th, 1902 (mostly 

 only broken valves). 



75. FRAGILARIA TENUICOLLIS. 



Var. ANTARCTICA. 



Frayilaria tennicollis Heib., Consp. crit. l)iat. danic. (1863), fig. XIII. ; Rabenhorst, Fl. Enrop. Alg., i. 



(1864), p. 119. 

 Var. antaretica W. and G. S. West, op. cit., p. 279, PI. XXVI., fig. 128. 



Long. valv. = 37-46 /a ; lat. valv. = 3-3 ' 5 p.. 



Ilab. Damp spot, summit of Cape Adare, January 9th, 1902 ; on ice, four feet 

 above frozen watercourse through ''Penknife ice," McMurdo Bay, September 13th, 

 1902; pond in ice off Black Island, McMurdo Strait, December 31st, 1902. 



This form was relatively abundant. Many of the valves were rather longer than 

 those recorded by Messrs. West. 



