410 Ciliophora 



Family 4. Ophrydiidae. The oral end of the body is prolonged into a 

 long contractile neck. The aboral end tapers to a point in some species 

 but is broadly rounded in others. The scopula may or may not produce 

 a short stalk. 



Only two genera have been recognized: Ophrydium Ehrbg. (106; Fig. 7. 44, C, I) and 

 Ophridiopsis Penard (106, 165). 



Family 5. Scyphidiidae. These are sessile peritrichs in which the scopula 

 functions as a holdfast organ. The body is sometimes broadly flattened 

 at the aboral pole; in other cases it tapers to a stalk-like basal region. 



Four genera have been assigned to the family: Ellobiophrya Chatton and Lwoff (25; 

 Fig. 7. 45, A-F), Glossatella Biitschli (106; Fig. 7. 44, A), Paravorticella Kahl (106; 

 Fig. 7. 44, B), and Scyphidia Dujardin (87, 106, 212; Fig. 7. 44, F-H). 



Family 6. Urceolariidae. This family includes specialized ectoparasites 

 and endoparasites in which the oral-aboral axis is often much shortened. 

 The aboral end is a flattened disc equipped with rings of cuticular ele- 

 ments (Fig. 7. 45, G). These skeletal elements o£ the basal disc seem to be 

 composed of scleroproteins and they have no continuity in fission, each 

 daughter organism forming a new set (68). Although the ribs and den- 

 ticles (or plates) of the basal disc have sometimes been considered impor- 

 tant in attachment to the host, their functional significance is somewhat 

 vmcertain. Cyclochaeta domerguei (146), for instance, is not really at- 

 tached to its host. The organism is equipped with a series of aboral loco- 

 motor structures (Fig. 7. 45, H, I) — a posterior row of membranelles, a 

 row of slender cirri just above the membranelles, and an undulating 

 velum, a delicate membrane lying above the cirri. The cirri are important 

 in swimming, whereas the membranelles are responsible for gliding move- 

 ments, spinning the ciliate counterclockwise, and at the same time holding 

 it in contact with the host. 



Kahl (106) included three genera in the family: Cyclochaeta Jackson (35, 146; Fig. 

 7. 45, G-I), Trichodina Ehrbg. (49, 68, 87, 161; Fig. 7. 46, I), and Urceolaria Stein (87, 

 228; Fig. 7. 46, F, G). Hirschfield (87) has discussed the suggestion of Faurc-Fremiet 

 that Cyclochaeta Jackson should be reduced to a sub-genus of Trichodina Ehrenberg. 

 This simplification of the family would recognize only two genera: Trichodina, in 

 which the denticles show projections (Fig. 7. 45, G); and Urceolaria, in which the 

 denticles (or plates) lack such projections (Fig. 7. 46, G). 



Family 7. Vaginicolidae. These are loricate peritrichs which differ from 

 the Lagenophryidae in that the entire oral end of the body is extended 

 beyond the mouth of the lorica. 



Seven genera have been assigned to the family: Caulicola Stokes (106; Fig. 7. 46, E), 

 Cothiirnia Ehrenberg (106; Fig. 7. 46, C), Platycola Kent (106; Fig. 7. 46, H), Pyxicola 



