Phylum Ciliophora [ 229 



Family Opalinoea Pritchard 1842. Family Opalinaea Siebold in Siebold and 

 Stannius Lehrb. vergl. Anat 1: 10 (1848). Family Opalinina Stein Org. Inf. 2: 169 

 (1867). Family Opalinidae Glaus 1874. Family Protoopalinidae Metcalf 1940. 

 There are about 150 known species of four approximately equally numerous genera: 

 Protoopalina Metcalf, cylindrical, with one or two nuclei which are always found in 

 a stage of mitosis; Zelleriella Metcalf, similar, the cells flattened; Cepedia Metcalf, 

 cylindrical, with many nuclei; Opalina Purkinje and Valentin, flattened and 

 m.ultinucleate. 



Order 2. Holotricha Stein Org. Inf. 2 : 169 ( 1867) . 



Orders Gymnostomata and Trichostomata, and suborder Aspirotricha Biitschli 



in Bronn Kl. u. Ord. Thierreichs 1: 1674 (1889). 

 Suborder Hymenostomata Hickson 1903. 

 Orders Gymnostomataceae and Aspirotrichaceae Hartog in Cambridge Nat. 



Hist. 1: 137 (1909). 

 Order Holotricha with suborders Anoplophryinea, Gymnostomata, and Hymeno- 

 stomata Poche in Arch. Prot. 30: 250-255 (1913). 

 Order Holotrichida Calkins Biol. Prot. 376 (1926). 

 Infusoria with differentiated macronuclei and micronuclei, with simple cilia dis- 

 tributed generally over the surface of the body, not having membranelles in a spiral 

 band about the cytostome. 



This group is the mass of the more primitive typical Infusoria, of numerous fami- 

 lies, not all of which are to be listed here. Arrangements of the families in other 

 groups than the three here maintained have been proposed and are presumably more 

 nearly natural. 



a. Cytostome anterior. Suborder Gymnostomata (Biitschli) Poche. Suborder 

 Gym.no stom,ina Hall. 



Family Enchelia Ehrenberg Infusionsthierchen 298 (1838). Family Enchelina 

 Stein Org. Inf. 2: 169 (1867). Family Enchelyidae Kent. Families Holophryidae and 

 Cyclodinidae Schouteden. Family Didiniidae Poche. Comparatively unspecialized 

 forms, radially symmetrical or nearly so. Enchelis O. F. Miiller; Holophrya, Chaenia, 

 Prorodon; Ichthiophthirius, becoming parasitic in the skins of fishes; Lacryviaria, 

 the cytostome at the end of an extensible proboscis; Didinium, barrel-shaped, with 

 the cilia confined to two belts, having an extensible proboscis by means of which it 

 seizes other Infusoria and through which it swallows them. 



Family Colepina Ehrenberg op. cit. 316 includes the single genus Coleps. The cells 

 look like hand grenades of World War I: they are approximately barrel-shaped (the 

 axis more or less curved), the pellicle forming hardened quadrangular plates between 

 which the cilia project. The anterior cytostome can be opened widely to ingest other 

 Infusoria. 



b. Cytostome lateral. Suborder Aspirotricha Biitschli. 



Family Parameciina Perty (1852). Family Paramoecidae Grobben. Paramaecium 

 [Hill] O. F. Miiller Verm. Terr. Fluv. 1: 54 (1773). The name is variously spelled; 

 the spelling here used is Miiller's in what is believed to be the first publication under 

 binomial nomenclature. 



Family Colpodaea Ehrenberg Infusionsthierchen 345 (1838). Family Colpodidae 

 Glaus 1879. Family Ophryoglenidae Kent 1882. Small forms, oval, bean-shaped, 

 or flattened. Ophryoglena, Glaucoma, Colpoda, Tetrahymena, and many others. 



