xxn, D, 5 Haughwout: Protozoa of Manila and Vicinity: I 209 



Subphylum INFUSORIA — Continued. 

 Class Ciliata— Continued. 



Order Holotrichida. — ^Similar cilia uniformly distributed over the body. 

 These may lengthen about the mouth. Trichocysts may be dis- 

 tributed over the body or restricted to special areas. 

 Suborder Gymnostomina. — ^The mouth opens only during food-taking. 

 There is no undulating membrane about the mouth. 

 Family Enchelinidae. — Mouth round or oval in outline and either 

 terminal or subterminal. Food-taking is usually a literal act 

 of deglutition. Typical genera: Enchelys Hill, 1752, Ehren- 

 berg, 1838; Actinobolus Stein, 1867. 

 Family Trachelinidae. — Body asymmetrical or distinctly bilateral. 

 The dorsal aspect is slightly arched. Mouth terminal or sub- 

 terminal and in some cases drawn out to form a long pro- 

 boscis. When an oesophagus or gullet is present, it usually 

 is supported by a framework of rods or a tubelike structure. 

 (Esophagus may be absent. Typical genus, Dileptus Dujar- 

 din, 1841. 

 Family Chlamydodontidae. — Mouth usually in the posterior region. 

 General body form kidney-shaped or oval. Mouth almost 

 always open. Pharynx supported by a framework of rods or 

 by a smooth, firm tube. 

 Subfamily Nassulinse. — ^The body is completely ciliated. Typical 



genus, Nassula Ehrenberg, 1833. 

 Subfamily Chilodontina. — ^Body generally flattened. The cilia on 

 the dorsal aspect are stronger, and they may be confined 

 to that region. Typical genus, Chilodon Ehrenberg, 1833. 

 Subfamily Erviliinas. — The invariable characteristic is the pre- 

 sence of a movable style, which arises from the posterior 

 ventral surface. The cilia are restricted to the ventral 

 surface or to a portion of it. Typical genus, Dysteria 

 Huxley, 1857. 

 Suborder Trichostomina. — .The mouth or pharynx is bordered at its 

 edge by an undulating membrane or membranes. The mouth is 

 always open. Ciliation is general. 

 Family Chiliferldae. — Peristome area absent or at best only partially 

 developed. Mouth in anterior half of the body or near the 

 middle. When present the pharynx is short. Typical genus, 

 Colpoda Muller, 1773. 

 Family Urocentridae. — The cilia appear as two broad zones around 

 the body at each end. Mouth is in the center of the ventral 

 side and is fitted with a long tubular pharynx. Typical genus, 

 Urocent7-um Nitsch, 1827. 

 Family Microthoracidat. — Small forms, asymmetrical, the mouth in 

 the posterior region. Cilia generally dispersed, but occasion- 

 ally limited to the oral region. One or two undulating 

 membranes may be present. Typical genus, Microthorax 

 Engelmann, 1862. 

 Family Paramecidse. — There is a large triangular peristome, ex- 

 tending from the left anterior edge of the body to the mouth, 

 which is sometimes in the anterior and sometimes in the 



