Order Thigmotrichida 



Family ANCISTROCOMIDAE Chatton and 

 Lwoff, 1939. About 23 genera; 12 with marine 

 representatives: Cnlligocineta, Crebricoma, 

 Goniocoma, Heterocineta, Holocoma, Hypocomw- 

 galma, Hypocomella, Hypocomides, Hypocomina, 

 Insignicoma, Isocomides, and Rnabella. Typi- 

 cally ectocommensal on gills of bivalves. See 

 Fenchel (1965a), Kozloff (1965 and earlier pa- 

 pers), and Raabe (1970b). 



Family CONCHOPHTHIRIDAE Kahl, 1934. 

 At least four genera; one, Cochiiophilns, with a 

 marine representative endocommensal in Phytia, 

 a tidal marsh pulmonate snail of the west coast. 

 See Kahl (1934a) and Raabe (1963b). 



Family CRATERISTOMATIDAE Jankowski, 

 1967. Contains Crateristoma kindi, a carnivore 

 on prostome ciliates found in association with 

 barnacles. See Jankowski (1968). 



Family HEMISPEIRIDAE Konig, 1894. Con- 

 tains at least 17 genera, of which nine have ma- 

 rine members: Ancistrospira, Ancistrum, Bo- 

 veria, Hemispeira, Isselma, Orchitophrya, Pla- 

 giospira, Proboveria, and Protophyra. Most are 

 ectocommensal on gills of bivalves; one is en- 

 dozoic in echinoderms. Nucleocorbula adherens 

 Santhakumari and Balakrishnan Nair, 1970, for 

 which the authors erected the family NUCLEO- 

 CORBULIDAE, keys out here. See Lorn, Corliss, 

 and Noirot-Timothee (1968), Fenchel (1965a), 

 and Raabe (1970a). 



Family HYPOCOMIDAE Biitschli, 1889. 

 Three genera ; two, Heterocoma and Parahypo- 

 coma, with marine representatives; ectocom- 

 mensal on solitary and colonial peritrichs, and in 

 branchial cavity of ascidians. See Chatton and 

 Lwoff (1949). 



Family HYSTEROCINETIDAE Diesing, 

 1866. Members of this family (at least 10 gen- 

 era) are typically endocommensal in terrestrial 

 and freshwater oligochaetes. See Raabe (1949) 

 and Kozloff (1960). 



Family SPHENOPHRYIDAE Chatton and 

 Lwoff, 1921. Four genera with marine repre- 

 sentatives: Gargarius, Lwoffia, Pelecophfya, 

 and Sphenophi-ya; ectocommensal on gills of bi- 

 valves. Mature form with no cilia (except in 

 genus Lwoffia), but budded larval forms with 



several rows of cilia. See Kozloff (1955), Do- 

 brzanska (1961), and Raabe (1970b). 



Family THIGMOPHRYIDAE Chatton and 

 Lwoff, 1923. Two genera, Conchophylluvi and 

 Thigmophyra, with marine repre.sentatives; 

 ectocommensal on gills of bivalves. Undulating 

 membrane difficult to observe in life. See Fen- 

 chel (1965a). 



The genus Peviculistoma, sometimes consid- 

 ered to be a member of this order, is included 

 here in the family PLEURONEMATIDAE (or- 

 der Hymenostomatida) . Recently, Small erected 

 a new order Scuticociliatida for certain hyme- 

 nostome and thigmotrich families apparently 

 related by particular features of stomatogene- 

 sis. 



Order Peritrichida 



Family EPISTYLIDIDAE Kahl, 1933. Four- 

 teen genera, of which at least three have marine 

 representatives: Epistylis, Opisthostyla, and 

 Rhabdostyla. They occur attached to algae or 

 the outer surfaces of copepods and barnacles, 

 (Epistylis) , on stalks of ascidians (Opistho- 

 styla) , and on polychaetes, midge larvae, and 

 sea cucumbers (Rhabdostyla). Individuals soli- 

 tary and colonial. See Kahl (1935); Lom 

 (1964). 



Family LAGENOPHRYIDAE Butschli, 1889. 

 At least two genera; one, Lagenophrys, with ma- 

 rine representatives, ectocommensal on crusta- 

 ceans. See Couch (1967). 



Family SCYPHIDIIDAE Kahl, 1933. Ten 

 genera, of which three have marine representa- 

 tives. Members of the genus Ellobiophi-ya occur 

 on Donax; Paravorticella occurs on polychaetes; 

 Scyphidia occurs on snails and polychaetes. See 

 Kahl (1935). 



Family URCEOLARIIDAE Dujardin, 1941. 

 Subfamily Urceolarinae contains the genera 

 Urceolaria, Leiotincha, Trichodinopsis, and Poly- 

 cycla that occur as ectocommensals on marine 

 invertebrates, on gills and res])iratory surfaces 

 of marine invertebrates, in the gut of snails, and 

 in the gut of sea cucumbers, respectively. The 

 subfamily Trichodininae contains eight genera, 

 of which seven have marine representatives. 

 Members of the genera Dipartiella, Trichodinel- 

 la, and Tripartiella occur attached to fish gills; 



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