170 The Mastigophora 



has been described in some species. However, it has been suggested that 

 in Vacuolaria (Fig. 4. 38, F) at least, a large contractile vacuole has pre- 

 viously been misinterpreted as a gullet (232). The lack of such a gullet 

 would suggest that the Chloromonadida are not closely related to the 

 Euglenida. The dividing nucleus of Vacuolaria (Fig. 4. 38, G), strikingly 

 different from the euglenoid type, points to the same conclusion, as does 

 the insertion of the fiagella (Fig. 4. 38, B, F). The fiagella of Gonyosto- 

 rnum semen, on the other hand, apparently arise from the base of the 

 triangular cavity, or "gullet" (70). A peculiar "supranuclear cap" (Fig. 

 4. 38, D), lying just anterior to the nucleus, occurs in Vacuolaria (232). 

 Various globular, discoid, or spindle-shaped bodies, subpellicular in dis- 

 tribution (Fig. 4. 38, C, H), have been interpreted as mucous globules 

 (15, 232) and as trichocysts (33). Upon discharge, such inclusions give 

 rise to filaments in Gonyostomum (33). The cytoplasm of Gonyostomum 

 semen (114) and Chattonella subsala (15) is differentiated into two zones, 

 apparently separated by a delicate membrane ("central capsule"), per- 

 haps merely an interface. The outer zone contains the chromatophores, 

 vacuome, fat globules, and trichocysts. Fission occurs in flagellate stages 

 of Chattonella (16) and Gonyostommii (69, 114), and in palmella stages 

 of Vacuolaria (Fig. 4. 38, K). Cysts with a thick membrane have been re- 

 ported in Gonyostomiun (69). 



The Chloromonadida are fresh water types whose ecological distribu- 

 tion may be somewhat restricted. Gofiyostotnum semen, for instance, 

 seems to be limited to the rather acid waters of marshes (114), 



Tfie following genera have been referred to the order: Chattojiella Biecheler (15, 

 16; Fig. 4. 38, A, B), Coelomonas Stein (231), Gonyostomum Diesing (33, 69, 70, 114; 

 Fig. 4. 38, H-J), Merotrichia Mereschkowski (Fig. 4. 38, C), Rhaphidomonas Stein, 

 Rickertia Conrad (43), Thaumatomastix Lauterborn, Thaumatomonas de Saedeleer 

 (246), Trentonia Stokes (264), and Vacuolaria Cienkowski (83, 232). Three of these 

 generic names are said to be invalid, since Rhaphidomonas is a synonym of Gony- 

 ostomum, and both Coelomonas and Trentonia appear to be synonyms of Vacuolaria 

 (232). The relationships of Thaumatomastix, Thaumatomonas, and Rickertia to Chat- 

 tonella, Gonyostomum, and Vacuolaria need further investigation. 



CLASS 2. ZOOMASTIGOPHOREA 



These flagellates have no chromatophores and they store lipids 

 and glycogen but apparently no starch or paramylum. Some are sapro- 

 zoic but there are many holozoic species. The body is generally rather 

 plastic and no cellulose membrane or test is produced. Many are small 

 and simple in structure, while others are perhaps as complex as any of 

 the Protozoa. Zoomastigophorea occur as parasites in various groups of 

 invertebrates, in all classes of vertebrates, and also in certain plants. As 

 free-living flagellates, they are found in the soil and in both fresh and 

 salt water. The life cycle is simple in the majority, but polymorphic 



