132 OOCTSTIS AND EREMOSPHJERA, 



Syn., O. asymmetrical^ . West, New Brit. Frw. Alga^, in J. R. 

 M. Soc, 1894, p.l4, PI. ii., f.27; O. crassa fS asymnietrica Chodat, 

 Alg. vertes, p. 190. This is a form of O. apiculata in which tlie 

 cells are unequally developed, the long axis through the apicula- 

 tions being slightly to one side of the midline. West gives long, 

 cell. 15-8/x, lat. cell. 7-8 -6 /x. 



Var. OBESA, n.var. (PI. viii., f.;5). 



Celluhe ovales, quani forma typica modice majores et aliquanto 

 latiores, utroque polo apiculo humillimo instruct??. 



Cell. veg. 18x11, 19x12, 21 x 13, 22 x 13, 23x15, 24x16, 

 34x25, 35x25//. 



Guildford (60, 146); Botany (95). 



Somewhat larger than the type, and considerably broader, oval. 

 The axial ratio varies from 1*4 to 1"6: 1*0. 



Var. siMPLiciOR, n.var. (PL viii., f.4-6). 



Cellular elliptico-lanceolatfv', lateribus anjualiter arcuatis ad 

 apices convergentibus, apicibus acuminatis baud inciassatis nee 

 apiculatis. 



Cell. veg. 11 X 7, 14x7, 14 x 8, 15x7, 15x8, 15 x 10, 16 x 10, 

 18xll/x. 



Guildford (23, 88); Auburn (57); Botany Bay (91). 



A simpler form of the type, generally found in company with 

 it. The apiculus is replaced by a pointed apex. 



OocvsTis SUBHEXAGONA, n.sp. (PI. viii., f.7). 



Celluhe parvje subhexagonje; lateribus in medio parallelis, ad 

 apices convergentibus; apicibus acuminatis baud incrassatis. 



Cell. veg. 12x7, 16x10, 17x9, 17x10, 20x12, 20x14, 

 21 X 13, 22 X 1.3, 25 x 14, 25 x 15, 26x 15, 26 x 17, 34 x 24/z. 



Guildford (45, 60, 70, 146); Auburn (49, 57, 149); .Sydney 

 Water (65); Duck Creek, Clyde (74); Botany Bay (91). 



Chloroplasts discoid. This form is very closely connected with 

 O. apiculata, being probably intermediate between var. ohesa 

 and O. anstralieusis mihi. Its axial ratio agrees with that of 

 the former, varying, as it does, from 1"4 to 1'8:1*0; average of 



