THE MASTIGOPHORA 139 



Stein ('59). D. With a constant body form and two dissimilar flagella : Tro- 

 pidoscyphus Stein ('78) ; Anisonema Duj. ('41) ; Entosiphoii Stein ('78) ; 

 Thaumatomastix Lauterb. ('99). 



Order 6. PHYTOFLAGELLIDA. Flagellated unicellular organisms with chlorophyl 

 and holophytic nutrition, or without chlorophyl, and saprophytic in nutrition. 

 They are sometimes classified as plants, sometimes as animals. 



Suborder i. CHLOROMONADINA. The body is somewhat plastic and without a dis- 

 tinct membrane ; with numerous discoid chromatophores but without stigmata. 

 Genera : Vacuolaria Cienk. ('7) \ Coelomonas Stein ('78). 



Suborder 2. CHROMOMONADINA. Small forms with strong tendency to colony- 

 formation. They are often inclosed in a gelatinous mass, or occupy cups. They 

 may or may not have chromatophores, which, if present, are yellow or yellowish 

 brown in color. Nutrition is usually holophytic, but holozoic and saprophytic 

 forms are occasionally present. There may be one or two flagella, which are 

 invariably directed forward. 



Family i. Chrysomonadidae. The body is rarely naked, but usually covered by a 

 gelatinous mass or by a hyaline cup. With one or two flagella at the anterior 

 end and with or without stigmata. One or two yellowish chromatophores are 

 invariably present. Nutrition is holophytic or holozoic, sometimes both. 

 Genera: A. With naked body which may be inclosed during resting stages in 

 a gelatinous mass. Nutrition either holozoic or holophytic. Chrysamaeba 

 Klebs ('90) ; Chromulina Cienk. ('7) ; Ochromonas Wysotzki ('87) ; Stylo- 

 chrysalis Stein ('78). B. With a shell or lorica in which the individuals 

 are attached. Nutrition is holophytic. Chrysococcus Klebs ('92) ; Dinobryon 

 Ehr. ('38) ; Chrysopyxis Stein ('78) ; Nephroselmis St. ('78) ; Hyalobryon 

 Lauterb. ('99). C. Individuals protected by a close-fitting membrane. Hy- 

 menomonas Stein ('78) ; Microglena Ehr. ('31) ; Mallomonas Perty ('76) ; 

 Synura Ehr. ('33) ; Syncrypta Ehr. ('33) ; Uroglena Ehr. ('33) ; Chryso- 

 sphcerella Lauterb. ('99). 



Family 2. Cryptomonadidae. The body has a firm cuticle and is never amoeboid. 

 There are two similar flagella, a peculiar oesophagus-like canal, and a contractile 

 vacuole in the anterior end. Two chromatophores of variable color may or may 

 not be present. Nutrition is holophytic or saprophytic. Genera: Cryptomonas 

 Ehr. ('31); C/rilomonasE\\r. ('31); Cyathomonas Fromentel ("74)- 



Suborder 3. CHLAMYDOMONADINA. Body-form more or less changeable. Color 

 usually green, and due to the presence of a large, sjngle chromatophore contain- 

 ing chlorophyl. A firm shell is usually present. The body has two or four 

 flagella, one or two contractile vacuoles, and a stigma at the anterior end. Re- 

 production takes place by continued division within the shell either during active 

 or resting phases. Macro- and micro-gametes may be formed. 



Family i. Chlamydomonadidae. With a stiff coating perforated only by minute 

 apertures for the flagella. Genera : Chlamydomonas Ehr. ('33) ; Chlorogonium 

 Ehr. ('35) ; Polytoma Ehr. ('38) ; Hcematococcus Agardh ('28) ; Carteria Diesing 

 ('66) ; Spondylomorum Ehr. ('48) ; Chlorangium Stein ('78). 



Family 2. Phacotidae. The body of the flagellate corresponds to that of Hcemato- 

 coccus, and is surrounded by a thick shell membrane which the body does not 

 fill. The shell is frequently bivalved. Genera : Coccomonas Stein ('78) ; Meso- 

 stigtna Lauterb. ('94) ; Phacotus Perty ('52) ; Tetratoma Butschli ('85) ; Pyra- 

 mimonas Schmarda ('50) ; Chlor aster Ehr. ('48). 



Suborder 4. VOLVOCINA. Colony forms. The individuals possess two flagella and 

 chlorophyl-bearing chromatophores. The number of individuals composing the 

 colony may be constant or variable ; when constant, the colony is formed by 

 regular cleavage, as in the eggs of Metazoa. Reproduction asexual by division 



