Order Hymenostomatida 



Family CINETOCHILIDAE Perty 1852. Two 

 genera, of which one, Cinetochilum, with one ma- 

 rine species. Free-living. See Gelei (1940). 



Family COHNILEMBIDAE Kahl, 1933. In- 

 cludes only the genus Cohnilemhus. Free-living. 

 See Borror (1961, 1963). 



Family ENTORHIPIDIIDAE Madsen, 1931. 

 Contains at least the genus Entorhipidium, oc- 

 curring in the gut of sea urchins. See Berger 

 (1961b). 



Family FRONTONIIDAE Kahl, 1926. Eight 

 genera; two with marine species: Frontonia 

 and Fronton iella. Widespread, free-living. See 

 Roque (1961). 



Family LOXOCEPHALIDAE Jankowski, 

 1964. At least two genera with marine species, 

 Dexiotricha and Loxocephalus. Free-living. 

 Cardiostomatella may belong here also. See 

 Jankowski (1964a) and Faure-Fremiet (1968). 



Family OPHRYOGLENIDAE Kent, 1880. 

 Possibly four genera; only one, Ophryoglena, 

 in the marine habitat. Free-living in brackish 

 waters; some species histophagic. See Roque 

 (1961). 



Family PARAMECIIDAE Dujardin, 1841. 

 One genus, Paramecium, with many species, of 

 which P. woodruffi and P. calkinsi occur in 

 brackish water. Free-living. See Wichterman 

 (1953). 



Family PHILASTERIDAE Kahl, 1931. The 

 boundaries between this family and the URONE- 

 MATIDAE are unclear. The members of the 

 genera Philaster, Philasterides, and Porpostoma 

 form a natural group within the PHILASTERI- 

 DAE. Anophrys salmacida may belong here also 

 (Small, 1967). Additionally, members of the 

 genera Glaticonema, Helicostoma, Paranophrys, 

 Parauronema, and Potomacus, most of which 

 have been placed in the URONEMATIDAE, may 

 be members of the PHILASTERIDAE. Free- 

 living and endocommensal in sea urchins, some- 

 times found in association with hydroids and 

 anemones, some histophagic. 



Family PLEURONEMATIDAE Kent, 1880. 

 Genera with marine members are Cristigera, 



Cyclidmm, Histiobalantium, Pleurocoptes, Pleu- 

 ronema, and Schizocalyptera. The genus Cycli- 

 dmm is sometimes placed in the family CYCLI- 

 DIIDAE Ehrenberg, 1838. The genus Penicu- 

 listoma, sometimes considered in the order 

 Thigmotrichida, may also belong in this family. 

 Free-living and commensal on mussels and sea 

 urchins. See Faure-Fremiet (1961a), Dragesco 

 (1968), and Borror (1963). 



Family PSEUDOCOHNILEMBIDAE Evans 

 and Thompson, 1964. On the basis of similari- 

 ties in morphogenesis, Pseudocohnilembiis spp. 

 and Anophrys sarcophaga belong here (Evans 

 and Thompson, 1964; Small, 1967) . On the basis 

 of interphase morphology, Paralembiis and 

 Cryptochilidium cuenoti may also belong here. 

 Free-living and endocommensal in sea urchins 

 (C cuenoti occurs in the esophagus of the sipun- 

 culid Phascolosoma) . See Berger (1961a, 1965) 

 and Mugard (1949). 



Family TETRAHYMENIDAE Corliss, 1952. 

 Includes at least six genera; two with marine 

 species: Paratetrahymena and Platynematum. 

 Recently Corliss (1961) split several genera 

 from this family and placed them in the family 

 GLAUCOMIDAE. See Borror (1962), Corliss 

 (1961), Czapik (1968), and Thompson (1963). 



Family URONEMATIDAE Thompson, 1964. 

 The boundaries between this family and the 

 PHILASTERIDAE are unclear, but members 

 of the genera Uro7iema and Uropedalium form 

 a well-defined group within this family. In ad- 

 dition, members of the genera Glauconema, Mi- 

 amiensis, Parauronema, and Potomacus have 

 been placed here. Free-living, sometimes found 

 in association with hydroids and anemones. See 

 Thompson (1964a, b, 1966) and Thompson and 

 Berger (1965). 



In addition to the hymenostomes assigned to 

 the families above, members of several genera 

 {Biggaria, Cinfptochilum, Entodiscus, and Mad- 

 senia, all endocommensals of sea urchins) are 

 considered here as hymenostomes with no as- 

 signed familial status (Berger, 1961c). 



Recently, Small erected a new order Scutico- 

 ciliatida for certain hymenostome and thigmot- 

 rich families apparently related by particular 

 features of stomatogenesis (Small, 1967). 



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