380 Ciliophora 



spiny collar or a toothed disc, the area anterior to which is non-ciliated. 

 A number of contractile vacuoles are arranged in one or two longitudinal 

 rows or distributed irregularly. Chains are usually formed. 



Two genera have been referred to the family: Intoshellina Cep^de (36, 84; Fig. 7. 

 28, A-C) and Monodontophrya Vejdowsky (36; Fig. 7. 28, D, E). 



Fig. 7. 28. A-C. Intoshellina poljansky Cheissin: primite and satellite 

 (A), x225; holdfast apparatus (B, C), polar and ventral views, x975 (after 

 C). D, E. Monodn?itoplirya kijenskiji Cheissin: anterior end (D), showing 

 thick ectoplasmic cap and holdfast organ, x650; lateral view (E), x75 (after 

 C). F, G. Maupasella criodrili Heidenreich, 50-1 50/i long; entire specimen 

 (F), skeletal apparatus (G), x3300 (after H.). 



Family 5. Manpasellidae. Little is known about this group which con- 

 tains only two genera, Maupasella Cepede (84; Fig. 7. 28, F, G) and 

 Schulzellina Cepede. These ciliates are similar to the Hoplitophryidae 

 and Cheissin (36) has suggested that further investigation might justify 

 combining the two families. 



In addition to the five families described above, Cheissin (36) included 

 the Chromidinidae, containing the genus Chromidina Gonder (= Opali- 

 nopsis Foettinger). Chatton and Lwoff (28), on the other hand, concluded 

 that Chromidina belongs in the Apostomina. 



Order 2, Spirotrichida. The most characteristic feature is the adoral 

 zone of membranelles, the narrow bases of which usually lie at right or 

 oblique angles to the long axis of the adoral zone. This series of mem- 

 branelles extends anteriorly from the left margin of the cytostome, and 

 in certain genera, may turn dorsally at the anterior pole and extend to 

 the right for some distance along the antero-dorsal surface. The basal 



