390 Ciliophora 



Suborder 2. Oligotrichina 



The somatic ciliation is either markedly reduced or has disappeared. 

 Persisting somatic cilia are often fused into tufts. The zone of mem- 

 branelles is commonly differentiated into a short oral band and an an- 

 terior spiral band of more powerful membranelles (Fig. 7. 34, A) which 

 are the most important or else the only organelles of locomotion. The 

 suborder is divided into two families. 



Fig. 7. 34. A, B. Halteria geleiana Szabo, antero-ventral view (A) showing 

 oral membranelles and membrane, anterior locomotor membranelles, and 

 lateral cilia ("Springborsten"), x400; polar view (B) of adoral organelles, 

 x800 (after S.). C, D. Strobilidium gyrans (Stokes) Kahl, about 60^ long: 

 polar view of peristome (C), schematic; lateral view (after K.). E. Lohmani- 

 ella elegans (Wiilff) Kahl, specimen 25/^ long (after K.). F. Tontonia gracil- 

 lima Faure-Fremiet, specimen 50/^ long; contractile protoplasmic fibre ex- 

 tends from the posterior part of the body (from Kahl, after F-F.). 



Family 1. Halteriidae. The peristome and the band of membranelles 

 extend posteriorly on the ventral surface. The group is represented in 

 fresh, salt, and brackish water. 



The following genera have been referred to the family: Halteria Dujardin (104, 209; 

 Fig. 7. 34, A, B), Meseres Schewiakoft (104), Metastrombidium Faure-Fremiet (104), 

 Strombidium ClaparMe and Lachmann (55, 60, 104), Tontonia Faure-Fremiet (104; 

 Fig. 7. 34, F). 



Family 2. Strohilidiidae. The zone of membranelles forms a spiral 

 crown at the anterior pole (Fig. 7. 34, C, D). The majority are marine, 

 biit some are known from brackish water and a few from fresh water. 



