522 PLANKTON OF THE SYDNEY WATER-SUPPLY, 



In our forms, the setae are often very tenuous, and some- 

 times quite weak and crinkled. They are rarely straight, 

 being generally curved either outwards or downwards. The 

 cells of this species exhibit three distinct shapes, viz., the 

 oblong form of L. genevensis, the pointed shape of our com- 

 mon Australian var. acu/mnafa, and the oval figure of the 

 type. The same three type-forms are found occurring also in 

 the variations with only two polar setae. A very common 

 size here, 12x8 or 12 x 9, is that given by Lemmermann for 

 Ghod. longiseta, and accords with the smallest dimensions in 

 Lagerh., Pedi. Protococc. o. Palm., p. 76, for Oocystis cilinta. 

 The only difference between these two is the greater length 

 of the setae in Lemmermann 's form. 



Var. coRONATA, n.var. (Plate liii., fig. 3). 



Cellula oblonga vel ovalis, utraque parte rotundata; setis 

 5-8 ascendentibus, late patentibus, saepe debilibus fluctuosis. 



Var. iNFLATA, n.var. (Plate liii., fig. 4-5). 



Cellula lateribus arcuatis, ad apices rapide convergentibus ; 

 apicibus plus minus acuminatis ; setis 5-8 vulgo late-patenti- 

 bus. 



Var. AMPHiTRiCHA(Lagerh.). (PI. liii., f.6). 



Cell. long. 9; lat. 8; setae 12//,. 



Cf. Lagerheim, Sveriges Algflora, T.i., f.2o, 26. 



Var. GKNEVENSis(Chod.). (PI. liii., f.7). 



Cellula matricalis interdum late-elliptica, utroque polo papilla 

 instructa; aplanosporis saepe binis. 



Cell, matric. long. 14-18; lat. 10-15; setae ad 30 /x. 

 Apian, long. 7-8; lat. 4 /x. 



It is important to note that the mother-cells found in the 



plankton were often identical in size and shape with Ghod. citri- 



formis Snow, but possessing the two polar setae of L. genevensis 



Chod. All these "'species" of Lagerheimia and Ghodatella are 



olymorphic forms of one true species. 



