THE FAUNA OF BOULDER COUNTY 243 



SuBPHYLUM Infusoria 



Protozoa in which the motor apparatus is in the form of cilia, either simple or 

 united into membranes, membranelles or cirri. The cilia may be permanent or 

 (Suctoria) limited to the young stages. With two kinds of nuclei, macronucleus 

 and micronucleus. Reproduction is effected by simple transverse division or by 

 budding (Calkins). 



Class CILIATA 



Ciliate in all stages. 



Order HOLOTRICEIDA 



Cilia alike and usually distributed all over the body (for exceptions see Chilodon- 

 tinje. Microthoracidffi, etc.), or longer in vicinity of mouth; trichocysts (poison 

 organs) present. 



Suborder Gymnostomina 



No undulating membrane about the mouth, which remains closed except when 



food is taken. 



Family ENCHELINID.ffi 



Mouth terminal or subterminal. 



(60) Coleps Ehrenberg. Ovate, persistent in shape; surface usually deeply fur- 

 rowed longitudinally and transversely, the furrows bearing cilia (Edmondson). 



C. hirtus Ehr.* 



(61) Mesodinium Stein. Ovate or pyriform, rounded posteriorly, produced into 

 a conical proboscis anteriorly. Our species* has not been determined. 



(62) Lacrymaria Ehrenberg. Elongate-oval or flask-shaped, anterior extremity 

 usually very narrow and neck-like, compared with that of a swan in L. olor. 



L. olor (Miiller);* L. trimcaia Stokes. 



(63) Prorodon Ehrenberg. Oval, without any neck or process, not furrowed as 

 is Coleps. P. teres Ehr.*; P. edentatus C. and L.* 



Family TRACHELIIDiE 

 Distinctly asymmetrical, with the dorsal side arched. 



(64) Lionotus Wrzesniowski. Elongate, slug-like animals. L. fasciola (Ehr.),* 

 contractile vesicle single, posterior; L. pleurosigma Stokes,* contractile vesicles 

 numerous. These animals are quite large, 100 m or more long. 



Family CHLAMYDODONTID^ 

 General form oval or kidney-shaped; mouth almost always posterior; pharynx 

 supported by a rod apparatus, or smooth, firm tube. 



Subfamily CHILODONTIN^ 

 Body generally flattened, and cilia stronger on dorsal side, or confined to that 



region. . j -^u 



(60 Chilodon Ehrenberg. Elongate-oval or oblong; the anterior end with a 

 more or less lip-like structure. C. cuctdlukis (Muller).* Length 125-200 M. 

 The young are in several respects unlike the adults. 



