CILIATA. 



47 



Fam. 1. Chilifera. Mouth in the anterior half of the body, or close behind 

 the middle. Pharynx either scarcely developed or short. The undulating 

 membranes stand either at the edges of the mouth or in the pharynx. A 

 so-called peristoniial field leading to the mouth absent or little developed. 



Leucophrys Ehrb., f.w. ; Glaucoma Ehrb., f.w. and infus. ; Dallasia St6kes, 

 f.Av. ; Frontonia Clap, and L., f.w. and m. ; Ophryoglena Ehrb., f.w.; Colpidium 

 Stein, f.w., infus., m. ; Chasmatostoma Engelmann, f.w.; Uronema Duj., f.w., 

 m., par. on skin of star-fishes ; Urozona Schewiakoff, f.w.: Loxocephalus Kent, 

 f.w. and infus.; Colpoda Miiller, f.w. and infus. (hay). 



Fam. 2. Microthoracina. Asymmetrical ; mouth in hinder part of body, 

 placed somewhat laterally at the anterior end of a peristoniial furrow, which 

 begins behind ; ciliation sometimes complete, sometimes confined to ventral 

 surface, always sparse. Cinetochilum Perty, 

 f.w., m. ; Microthorax Engelmann, f. AV. ; 

 Ptychostomum Stein, paras, in intestine of 

 Oligochretes ; Ancistrum Maupas, in mantle 

 cavity of Mytilus, Venus, and probably 

 Ostrea ; Drepanomonas Fresenius, f. w. 



Fam. 3. Paramaecina. Mouth sometimes 

 in the anterior, sometimes in the hinder half 

 of the body, with considerable triangular 

 shallow peristoniial pit passing to it from the 

 left side of the body. Pharynx tubular, with 

 long undulating membranes or row of cilia. 

 Ciliation close and uniform. Paramcecium 

 Hill (Fig. 37-39), f.w. and m. 



Fam. 4. Urocentrina. Mouth in middle 

 of ventral surface with long tubular pharynx, 

 like that of Paramcecina. Ciliation reduced 

 to two broad annular zones, one in front 

 and one behind. Urocentrum Nitzsch, f.w. 

 and m. 



Fam. 5. Pleuronemina. Ciliation complete 

 and usually considerable ; mouth at the end 

 of a peristome placed at varying distances 

 from the front end on the ventral surface. 

 The left edge of the peristome with con- 

 siderable undulating membrane ; the right 



edge with a weaker membrane, or with a row of closely-placed cilia. Pharynx 

 slightly developed or absent. Lembadion Perty, f.w.; Pleuronema Duj., f.w. 

 and m.; Calyptotricha Phillips ; Lembus Cohn, f.w., infus., m. 



Fam. 6. Isotrichina. Pellicle thick ; ciliation total and close. Mouth 

 posterior. Parasitic in rumen of Ruminants. Isotricha Stein ; Dasytricha 

 Schuberg. 



Fam. 7. Opalinina. Ciliation complete and almost always uniform ; mouth 

 and pharynx absent. Anoplophrya intest. of Oligochretes, Polychretes, Clepsine, 

 Paludina ; Hoplitophrya Stein, with two hook-like structures, Oligochfetes and 

 Planarians ; Discophrya Stein, with anterior sucker, Planarians and Anura ; 

 Opalinopsis Foettinger, macronucleus in young forms elongated and twisted, 

 later an irregular, even branched and anastomosing mass breaking up into 

 pieces ; venous appendages of Sepia, Octopus, or in liver of Sepiola and Octopus ; 



FIG. 38. Paramcecium burso^ria about 

 one hour after conjugation (after 

 Biitschli). n micronucleus ; N 

 macronucleus ; PV contractile 

 vacuole. 



