THE INFUSORIA 



409 



regarded by Claparede and Lachmann and Lieberkiihn as young stages of 

 Stentor. Freshwater. 



Family HALTERINA, Cl. and L. Strombidium, Cl. and L. More or 

 less conical in shape, with a spiral adoral zone of long and strong cilia. 

 There are in addition a few cilia on the ventral surface. 0'04. Marine 

 and freshwater. (Fig. 65.) Torquatella, Lankester. Closely related to 

 Strombidium, but with adoral cilia united to form a membranous collar. 

 A supra-oral papilla. (Figs. 12 and 66.) Found associated with the 

 eggs of Terebella. Halteria, Duj. Spherical in form, with tactile pro- 

 cesses scattered on the posterior hemisphere of the body. It remains 

 motionless for some time and then suddenly darts forward to another 

 position, where it again assumes its immobility. 0'04. Freshwater. 



Family TINTINNOINA, Clap, and L. These are minute forms which 

 build a gelatinous or chitinous protective shell or case. Tintinnidium, 

 Saville Kent. The case is gelatinous and tubular, sometimes free, some- 

 times attached to foreign objects. Freshwater. Tintinnus, Fol. With a 



Fio. 05. 



Strombidium claparedii, 

 Kent, a, meganucleus ; 

 b, contractile vacuole. 

 x 200. 



Fio. 66. 



Torqitatella typica, 

 Lankester. Side view 

 to show the supra- 

 oral papilla (/>) as 

 seen through the 

 membranous collar. 

 Cf. Fig. 12. 



Fio. 67. 



Codonella lage- 

 nula, Cl. and L. 

 X 200. 



Fio. 68. 



Empty shell of 

 Codonella campa- 

 nella, Haeckel. 

 x 180. 



chitinous shell shaped like a test-tube with a slightly constricted neck. 

 0*3. Marine. Tintinnopsis, Stein. Shell conical in shape, very thin, and 

 sometimes strengthened by agglutinated foreign particles. 0'2. Pelagic 

 plankton. Codonella, Haeckel. Pot-shaped shell, ornamented with hexa- 

 gonal ridges. (Figs. 67 and 68.) In some species there is an apparatus 

 for closing the orifice of the shell. O'l. Marine and freshwater. 

 Ptychocylis, Brandt. Marine. Porella, Cleve. Marine. Didyocysta, Ehrb. 

 O'l. Marine. 



Family OPHRYOSCOLECINA, Stein. The following genera composing 

 this family occur in the rumen of the cow and some other Artiodactyla. 

 Ophryoscolex, Stein. At the anterior extremity there is a funnel-shaped 

 peristome provided with many large cilia. Running spirally round the 

 anterior end of the body there is an adoral membranella provided with a 

 few thick cilia. There is a well-marked anus. At the posterior end of 

 the body there is a spinous prolongation of the cortex, and similar spinous 

 processes occur in circular elevations for some considerable distance in 

 front of it. There are several contractile vacuoles. 0'1-0'3. Entodinium, 

 Stein. Oval in form, with a spinous caudal process. No spiral mem- 



