398 Ciliophora 



The zone of membranelles often extends from the cytostome anteriorly 

 and then transversely across the antero-dorsal or antero-ventral surface of 

 the body (Fig. 7. 39, H). In the Aspidiscidae, however, the membranelles 

 are reduced to a short band (Fig. 7. 39, B). An undulating membrane 

 often extends at least part way along the right margin of the peristome 

 (Fig. 7. 40, A). 



Family 1. Aspidiscidae. These are flattened ciliates (Fig. 7. 39, A) with 

 an armor-like pellicle. The adoral membranelles are reduced to a short 

 band, while the cirri are limited to a small group of frontals and a group 

 of anal cirri (Fig. 7. 39, B). Near the anterior end there is sometimes a 

 small depression containing a few delicate membranelles which represent 

 the anterior remnant of the primitive adoral zone. 



The type genus, Aspidisca Ehrenberg (104; Fig. 7. 39, A, B, D), seems to be the only 

 one which belongs to the family. Chatton and Seguela (34) have referred their genus 

 Euplotaspis (Fig. 7. 39, G) to the Aspidiscidae but such an assignment cannot be justi- 

 fied without major revisions in characterization of the family. Perhaps a better location 

 for Euplotaspis would be the family Paraeuplotidae. 



Family 2. Euplotidae. The number of ventral cirri is reduced, with a 

 loss of the right marginal series (Fig. 7. 39, C) or both marginal rows 

 (Fig. 7. 39, H) and usually of all except a few of the primitive ventral 

 group. The persisting cirri are relatively stout and there is generally a 

 group of well-developed anal cirri (usually five). A few caudal cirri also 

 persist, either as rather slender structures or as large "rudders" in 

 Uronychia and Diophrys. The peristome and the adoral membranelles 

 are well developed. 



The following genera are included in the family: Certesia Fabre-Domergue (104, 

 188; Fig. 7. 39, C), Diophrys Dujardin (104, 188; Fig. 7. 40, H), Euplotes Ehrenberg 

 (104, 170; Fig. 7. 40, G), Euplotidium Noland (158; Fig. 7. 39, H, I), and Uronychia 

 Stein (13, 104, 227; Fig. 7. 39, E, F). 



Family 3. Oxytrichidae. The arrangement of the cirri follows the gen- 

 eralized pattern, although there is some reduction of the ventral cirri in 

 certain species. Right and left marginal cirri are always present and the 

 adoral membranelles are well developed. 



The following genera have been referred to the Oxytrichidae: Ancystropodium 

 Faure-Fremiet (104), Balladyna Kowaleski (104; Fig. 7. 40, B), Balladynopsis Ghosh 

 (104), Caryotricha Kahl (104), Chaetospira Lachmann (104), Cladotricha Gajevskaja 

 (104), Epiclintes Stein (13, 104), Eschaneustyla Stokes (104), Gastrocirrhus Lepsi (13; 

 Fig. 7. 41, K), Gastrostyla Engelmann (88, 104, 223; Fig. 7. 40, F), Gonostomum Sterki 

 (104), Hemicycliostyla Stokes (104). Holosticha Wrzesniowski (88, 104; Fig. 7. 40, I; 

 41, A), Hypotrichidium Ilowaisky (182; Fig. 7. 41, G), Kahlia Horvath (89, 104; Fig. 7. 

 41, H), Keroria Ehrbg. (104; Fig. 7. 41, E), Onychodromopsis Stokes (104), Onychodromus 

 Stein (104; Fig. 7. 40, J), Oxytricha Ehrbg. (10. 88, 104; Fig. 7. 40, E), Paraholosticha 

 Kahl (88, 104; Fig. 7. 41, A), Pleurotricha Stein (104; Fig. 7. 41, C), Pseudostrombidium 



