Ciliophora 371 



of the body, and in certain species, the cytostome lies at the posterior 

 pole. Some specialized genera have lost the cytostome and developed an 

 anterior suctorial tentacle. Except in primitive types, there is reduction 

 of the somatic ciliature and this trend reaches a climax in genera which 

 retain only the thigmotactic cilia. 



Chatton and Lwoff (30) have listed six families. In three ("Tribe 

 Stomodea") — Conchophthiriidae, Hemispeiridae, Thigmophryidae — the 

 cytostome is functional and the adoral ciliature is recognizable. In the 

 others ("Tribe Rhynchodea") — Ancistrocomidae, Hypocomidae, Spheno- 

 phryidae — the adoral ciliature has undergone regression and there is no 

 functional cytostome, although a suctorial tentacle serves for the ingestion 

 of food much as in the Suctorea. 



Family 1. Ancistrocomidae. These ciliates are ovoid, pyriform, or some- 

 what cylindrical, typically with a more or less pointed anterior pole. The 

 closely set thigmotactic cilia, not as long as the somatic cilia, are limited 

 to a few short anterior fields. The body is extensively ciliated in certain 

 genera; in others, cilia may be limited to the thigmotactic fields. An an- 

 terior suctorial tentacle (Fig. 7. 23, B, G), continuous with an internal 

 canal, is characteristic. This tentacle enables the organism to become 

 attached to epithelial cells and ingest their contents. 



The following genera have been referred to the family (31): Ancislrocoiua Chatton 

 and Lwoff (— Parachaenia Kofoid and Bush) (128; Fig. 7. 23, H). Anisocomides Chatton 

 and Lwoff (31), Cepedella Poyarkoff (31), Crebicoma Kozloff (126; Fig. 7. 23, A), 

 Enerthecoma Jarocki (129; Fig. 7. 23, J), Goniocoma Chatton and Lwoff (31), Hetero- 

 cineta Mawrodiadi (125, 129; Fig. 7. 23, G), Heterocinetopsis Jarocki (31), Holocoma 

 Chatton and Lwoff (31), Hxpoconiagalma Jarocki and Raabe (128), Hypoconiatidium 

 Jarocki and Raabe (31; Fig. 7. 23, E), Hypocoinella Chatton and Lwoff (31), 

 Hypocomoides Chatton and Lwoff (127; Fig. 7. 23, B), Hypocomidium Raabe 

 (31), Hypocomina Chatton and Lwoff (126; Fig. 7. 23, D), Insignicotna Kozloff (127; 

 Fig. 7. 23, C), Isocomides Chatton and Lwoff (31), Raabella Chatton and Lwoff (31), 

 Syri7igupliary)ix Collin (31, 106). 



Family 2. Conchophthiriidae. There is a functional cytostome in the 

 posterior half of the body. The thigmotactic cilia are represented by the 

 anterior portions of somatic rows instead of forming separate fields. 

 The body is laterally compressed and the cytostome lies on the narrow 

 ventral surface (102). 



The following genera have been referred to this family: Atidreula Kahl (106), 

 Cochliophilns Kozloff (124; Fig. 7. 23, I), Conchophthirius Stein (106, 111; Fig. 7. 23, 

 F), Kidderia Raabe (46, 108). 



Faynily 3. Hemispeiridae. These are rather heavily ciliated types with a 

 posterior or subterminal cytostome. The adoral ciliature shows two typical 

 components (Fig. 7. 24, B). On the right a single row, row 1, curves 

 slightly to the left throughout most of its length and then sharply to the 



