XIII, D, 5 Haughwout: Protozoa of Manila and Vicinity: I 211 



Subphylum INFUSORIA — Continued. 

 Class Ciliata — Continued. 

 Order Heterotrichida — Continued. 

 Suborder Polytrichina — Continued. 



Family Stentoridse. — The relatively short peristome is limited to 

 the anterior end of the body, its plane lying at approximately 

 right angles to the long axis of the body. There is an adoral 

 zone of cilia, which may completely encircle the edge of the 

 peristome or may end at the right-hand edge. The surface 

 of the peristome is ciliated and shows spiral striations. The 

 body is often highly contractile. There are no undulating 

 membranes. Typical genus, Stentor Oken, 1815. 

 Suborder Oligotrichina. — The ciliation is reduced and limited to cer- 

 tain localized areas. 

 Family lieberkiihnidse. — Includes forms that were first thought to 



be young stentors. Little is known of them. 

 Family Halteriidse. — The ciliation is scant and scattered over the 

 ventral and dorsal surfaces. The peristome is not provided 

 with cilia. Typical genus, Halteria Dujardin, 1841. 

 Family Tlntinnidae. — The body is contained in a cup or theca, to 

 which it is attached by a stalk. There is a ring of paroral 

 cilia inside of the adoral zone of membranelles. Typical genus, 

 Tintinnopsis Stein, 1867. 

 Family Ophryoscolecidae. — Distinct spinelike processes appear at 

 the posterior end, and there is a well-defined anal tube that 

 leads to the anal pore. The peristome is deep and funnel- 

 like. The cuticle is thick. See Family Isotrichidae. Typical 

 genus, Opkryoscolex Stein, 1859. 

 Order Hypotrichida. — In this order the cilia are limited to the ventral 

 surface of a body that shows marked dorsoventral flattening. The 

 cilia are frequently fused to form brushlike cirri, which are used 

 as creeping organs and which may have a tactile function. There 

 is an adoral zone of membranelles. Bristles are frequently present 

 on the dorsal surface. The pharynx may be slightly developed or 

 altogether absent. 

 Family Peritromidae. — There are no cirri, the cilia on the ventral 

 surface being uniform in size and arrangement. The peristome 

 is but slightly differentiated from the rest of the frontal area. 

 Typical genus, Peritromus Stein, 1862. 

 Family Oxytrichidse. — The structure of some members of this family 

 is often quite complex. Some species, however, are more prim- 

 itive, somewhat resembling those in the family Peritromidae, the 

 ciliation on the ventral surface being uniform. Even here, some 

 of the anterior and some of the posterior cilia are fused to form 

 cirri that are spoken of as frontal and anal cirri, respectively. 

 In the greater number of species all of the cilia are thus modified. 

 There are strong marginal cirri that occur in perfect rows, while 

 the ventral cirri are less regularly arranged. There is an un- 

 dulating membrane on the right side of the peristome, which 

 is in addition to the adoral zone of membranelles, and in some 

 cases, a row of cilia between this membrane and the adoral 

 zone. These are the paroral cilia, which form the paroral zone. 



