32 



PROTOZOA. 



The following three families of the Isomastiyoda are separated as a sub-order 

 named Phytomastigoda on account of their plant-like features. 



Sub-order 5. PHYTOMASTIGODA. 



Holophytic, vegetable-like Isomastigoda with chlorophyll, without mouth. 



Fam. 17. Chrysomonadina. Solitary or colonial ; rarely with test ; with 



two, rarely one, brown to greenish-brown chromatophore ; usually with eye-spot 



at the base of flagella ; colonies free-swimming, with spherical grouping of 



individuals. Styfochrysalis Stein ; Chrysopyxis Stein ; Ncphrosclmis Stein ; 



Synura Ehrb., colonial, with cuticle often growing 

 out into fine spines ; Syncrypta Ehrb. 



Fam. 18. Chlamydomonadina. Almost always 

 green on account of considerable, usually single, 

 chromatophore ; usually delicate membranous shell 

 without large opening ; one to two contractile 

 vacuoles at base of flagella ; usually one eye-spot 

 (stigma). Reproduce by continued division within 

 the shell-membrane ; usually forming macro- and 

 niicrogonidia ; mostly solitary. Hymcnomonas 

 Stein: Glilorangium Stein; Chlorogonium Ehrb.; 

 Polyto-ma Ehrb., saprophytic, without chromato- 

 phores, with amylum bodies ; Chlamydomanas 

 Ehrb. ; Hcematococcus Agardh. ; Spondyl&morum 

 Ehrb., colonial; Coccomonas Stein; Phacotus 

 Perty. 



Fam. 19. Volvocina. Billagellate colonial 

 Phytomastigoda, intermediate in structure between 

 Ghlamydomonas and Hcematococcus. Reproduction 

 by continued division of all, or of certain, indi- 

 viduals of the colony (parthenogonidia] to form 

 daughter colonies. In some, probably in all, con- 

 jugation occurs between definite individuals of the 

 colony, with or without differentiation of the 

 colonies and gametes into male and female. The 

 result of conjugation is a resting zygote, which 

 develops later into one or into several new colo- 

 nies. Gonium 0. F. Miiller (Fig. 24), colonies of 

 o, colony, l, one f our or sixteen individuals united to a quadran- 

 A- collar; * mi- ,. ., late . like gro up ; reproduction by simul- 

 cleus ; Cv contractile vacuole ; f , , . , . . , , * ,. 



Xv oral vacuole taneous division ol all the individuals to form 



daughter colonies ; Stcphanosphcern Colin ; Pan- 

 dor ina Bory de Vincent; Eudorina, Ehrb.; Volvov L., spherical colonies with 

 numerous individuals, which are placed at equal distances within the common 

 thick colonial membrane, and lie in special membranes which stand off from 

 the cells and are compressed against one another into the form of hexagons. 



Cv 



I 



ni. 20. Codosiyc. Mrytiit (after 



Butschli). 



inclividual. 



Order 2. CHOANOFLAGELLATA. 



iijojjliora irith a collar-lilo' process <>f protoplasm roun<l the 

 base of the single flagellum. 



Solitary and colonial forms are included in this group. The 



