552 PLANKTON OF THK SYDNKY WATER-SUPPLY. 



Fig. 32. — Ehizo. eriensis var. morsa, a specimen which shows that 

 the diatom twists round its long axis to form those frus- 

 tules with the spines on opposite sides. From nature 

 (x700). 



Figs. 33-35. • — ■ var. Zachariasi (Brun)( x 528) ; 



frustales with inchoate corners growing into a perfect 

 rectangle prior to deduplication. 



Figs. 36-38. — — — — var. Zachariasi (Brun)(x700). 



J^rom Brisbane. 



Fig.39.— — var. gracilis (H. L. Smith)(x528). 



This .series furnishes indisputable evidence of the growth of the 



diatomic membrane. 



Plate Ivii. 



Figs. 1-3. — Feridinium tohulatum (Ehr.) ; (1) obverse, (2) hypo- 

 valve, (3) epivalve (x52S). 



Fig. 4. — Stages in the development of Peridiniu'm from the resting 

 cell, (a) Resting cell, (ft) (c) (e) the formation of hypo- 

 valve and epivalve, (d) the simple Feridinium shape. All 

 non-motile ( x 528) . 



Fig. 5. — Dinohryon sertularia 'Ehr., forma (700). 



Fig. 6. var. cyim(/r/rw/m (Imhof) (x 700). 



Fig. 7. var. diverge ns (Imhof) (x700). 



Fig. 8. var. Schaiiinslandii (Lemm.)(x700). 



Fig. 9. — Lindia torxdosa Dujardin ; (a) jaws. 



Fig. 10. — Trachelomonas caudafa (Ehr.) Stein (x700). 



Fig. 11. ■■ var. elegantissima (G. S. West) 



(x700). 



Fig. 12. — Mnllnmonas ."sp/f nf?r/).s (G. S. West), living specimen from 

 Botany swamps, chromatophores omitted (x 700). 



Fig. 13. . — two empty tests from the plankton 



(x528). 



Fig. 14. — ChJamydomonas intermedia. Chodat; (a) (x700), (6) 

 globular coenobium of 16 cells (x528). 



Fig. 15. ■ — — — ^sp. An 8-celled disciform coenobium 



(x700). 



Figs. 16-17. — I'ejnmyora palustris Greef var. echinulata, n.var. ; 

 (16) a large specimen just divided (x350). 



Fig. 18. — (iymnodiniitm fuscum var. cornifax (Schilling) (x350). 



Fig. 19. encysted (x528); (a) 



another cyst in back view, development more advanced 

 (x528). 



Fig. 20. — Coihurnia amphorella Maskell ; full-grown forms (x350). 



Fig. 21. . — (a) Maskell's type, a young speci- 

 men ; (b) one that has become fixed by the side (x350). 



Fig. 22. — Mennidiiim pelhnnhi'm Verty var. inflnfuw, n.var.(x400). 



