336 



Phacotus reticulatus, n.sp. (PL xlii., f.l6.) 



Cellulee a fronte visse circulatse; margine glabra; papilla humil- 

 lima inter setas; membrana insequaliter reticulata, colore dilute 

 rufescente; a latere ovales (ut videtur). 



Long. = lat. = 22/x. 



Lismore (246) 



The lenticular form of the type is only a specific distinction, 

 and not characteristic of the genus. 



Genus G o N i u m Miiller. 



GoNiUM PECTORALE Miiller. 

 Coen. long. 40, lat. 44 [x. 

 Lismore (236, 237, 239, 260). 



Genus Pandorina Bory. 

 Pandorina morum (Miill) Bory. 



Coen. long. 31-36, lat. 25-32 /x. 



Lismore (221, 237, 244, 246, 249). 



Var. TROPICA, n.var. (PI. xliv., f.l8.) 



Forma magna, ccenobio ovali ; cellulis magnis conicis dis- 

 junctis. 



Coen. long. 52-70, lat. 44-60; cell. diam. 9-14 /x. 



Lismore (242). 



Our Australian specimens of Pandorina morum seem to differ 

 somewhat from the European. G. S. West, Br. Frw. Alg., p. 192, 

 says: "The ccenobia are spherical or subspherical . . ." and, with 

 this, his fig. 76 A agrees. So also Chodat, Alg. Vertes, p. 150, 

 "Colonies globuleuses ou subglobuleuses . . . ." and his fig.58,xi., 

 p. 123. Our forms are invariably oval, cf. Stein, T.xvi., f.l4, 15; 

 I have never seen a spherical specimen. Var. tropica is rare, 

 twice as large as usual, and the cells more isolated. The latter 

 are arranged in three layers, whose planes are parallel to the 

 long axis of the coenobium, viz., a central ring of 10, above and 

 below which is a rosette of 6-}-l. The cells do not reach the 

 centre. Were it not that the sexual reproduction and germina- 

 tion of the zygotes are reported to be different (G S. West, I.e., 

 pp. 193-4), I should consider var. tropica to be an intermediate 



