I I O PROTOZOA 



II. Food taken in at a definite point or points, or by absorption, or 

 nutrition holophytio. 



1. No reticulate siliceous shell. Diameter under 500 /x (1/50"). 

 * Contractile vacuole simple (one or more). 



(u) Colourless : reserves usually fat : holozoic, saprophytic or 

 parasitic . . . .2. Pb,otomastigaceae 



(/J) Plastids yellow or brown : reserves fat or proteid : nutrition 

 variable : body naked, often amoeboid in active state (0. nudae), 

 or with a test, sometimes containing calcareous discs 

 (" coocoliths," " rhabdoliths ") of peculiar form (0. loricatae) 



3. Chrybomonadaceae 

 Ghromulina Cienk. ; Ghrysamoeba Klebs ; Hydrurus Ag, 

 Dinohryon Ehrb. (Pig. 37, 11) ; Syncrypta Ehrb. (Fig. 37, 12) ; 

 Zooxanthella Brandt ; Pontosphaera Lohm. ; Coccolithophora 

 Lohm. ; Bliabdosphaera Haeok. 

 (y) Green, (more rarely yellow or brown) or colourless : resei'ves 

 starch : fission longitudinal . . 4. Cr^ptomonadaceae 



Gryptomonas Ehrb. (Fig. 37, 9) ; Paramoeba Qreelf. 

 (6) Green (rarely colourless) : fission multiple, radial 



5. Volvocaceae 

 ** System of contractile vacuoles complex, with accessory formative 



vacuoles or reservoir, or both. 

 (e) Pellicle delicate or absent : pseudopodia often emitted : 

 excretory pore distinct from flagellar pit : reserves fat. 



6. Chloromonadaoeae 

 Ghloramoeba Lagerheim ; Tkaumatomastix, Lauterborn. 

 {() Pellicle dense, tough or hard, often wrinkled or striate : con- 

 tractile vacuole discharging by the flagellar pit. Nutrition 

 variable . . . . .7. Euglenaoeae 



Eaglena Ehrb. ; Astasia Duj. (Fig. 37, 3) ; Anisonema Duj. ; 

 Eutreptia Perty (Fig. 42, p. 124); Trachelomonas Ehrb. (Fig. 

 37, 1) ; Gryptoglena Elirb. 



2. Skeleton an open network of hollow siliceous spicules. Plastids 

 yellow. Diameter under 500 /i. . 8. Silicoflagellata 

 Dictyocha Ehrb. 



3. Diameter over 500 jj.. Mouth opening into a large reticulate 

 endoplasm : flagella 1, or 2, very unequal. 9. Oystoflagellata 

 Noctiluca Suriray (Fig. 48); Leptodiscus B,. Hertw. 



B. Fission oblique or trajisverse : flagella two, dissimilar, the one coiled 



round the base of the other or in a traverse groove ; pellicle often dense, 



of numerous armour-like plates . . 10. Dinoflaqellata 



Ceratiwm Schrank ; Gymnodinium Stein; Peridinium Ehrb. (Fig. 46); 



Pouchetia Schiitt ; Pyrocystis Murray (Fig. 47); Polyhrihos Biitschli. 



The Protomastigaceae and Volvocaceae are so extensive as to require 

 further subdivision. 



Protomastigaceae 



I. Oral spots 2. Flagella distant in pairs. . . Distomatidae 



II. Oral spot 1 or 0. 



