PROTOZOA 



II. Food taken in at a di-tiiiite point or points, or by absorption, or 

 nutrition liolopliytic. 



1. No reticulate siliceous shell. Uianiuter under 51)0 jj. (1/50"). 

 * Contractile vacuole simple (one or more). 

 ((*) Colourless : reserves usually fat : liolozoic, saprophytic or 



parasitic . . . .2. Protomastigaceae 



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



variable : body nalced, often amoeljoid in active state (C nudae), 



or with a test, sometimes containing calcareous discs 



(" coccoliths," " rhabdoliths ") of jjeculiar form (C loricatae) 



3. Chrysomonadaceae 



ChromiUiiia Cieuk. ; Chrysainoeha Klebs ; Hydrurus Ag. 



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



Zooxanthella Brandt ; Pontosphaera Lohm. ; Coccolithophora 



Lohm. ; Rhahdosphaera Haeck. 

 (y) Green, (more rarely yellow or Ijrown) or colourless : reserves 



starch : fission longitudinal . . 4. Crvpto.monadaceae 



Gryptomonas Ehrb. (Fig. 37, 9) ; Faramoeba Creetf. 

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



5. VOLVOCACEAE 



'^* System of contractile vacuoles complex, witli accessory formative 

 vacuoles or reservoir, or both. 



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

 excretory pore distinct from fiagellar pit : reserves lat 



6. Chlorojionadaceae 

 Chloravioeba Lagerheim ; Thauimttomastvx, Lauterljorn. 



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

 tractile vacuole discharging by the flagellar pit. Nutrition 

 variable . . . . .7. Euglexaceae 



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

 EiUreptia Perty (Fig. 42, p. 12-J); Trachelomonas Elirb. (Fig. 

 37, 1) ; Gryptocjlena Elirb. 



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

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

 IHctyocha Ehrb. 



3. Diameter over 500 /x. JMoutli opening into a large reticulate 

 endoplasm : flagella 1, or 2, very une([ual. !). Cystoflagellata 

 Nodiluca Suriray (Fig. 48) ; Leptodisctis 11. Hertw. 



1j. Fission oblique or transverse : flagella two, dissiniilai', the one coiled 



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



of numerous armour-like plates . . 10. Dinoplagellata 



Ceratiuni Schrank ; Gymnodinium Stein; Pendininm Elirb. (Fig. 46); 



Fouchetia Schiitt ; Pyrocystis Murray (Fig. 47); Folykrikos 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. 



