SMITH : INFUSORIA OF KANSAS. 159 



Tillina magna Gruber. 



Body broadly bean-shaped, laterally compressed, about twice as long 

 as broad. Contractile vacuole located in a lobe which extends dorsally 

 from the posterior part of the body. Oral aperture near the middle of 

 the ventral surface. Pharynx recurved and dilated at its inner end, its 

 walls completely ciliated. Cuticular surface smooth. Apparent striations 

 radiating from the posterior part of the animal forward, in the lower 

 layer of the body. Macronucleus oval, located in the anterior half of 

 the body. 



Although this is generally considered to be a rare species, it appeared 

 in two of my hay infusions in great abundance, and lived for several 

 weeks without any special care. This was in the early spring. Repro- 

 duction occurred frequently through the formation of cysts and subse- 

 quent division into two or four. Miss Gregory found the species in a 

 culture of horse manure, and regarded it as a possible parasite of the 

 horse. I have found nothing to indicate that this is so. 



Length of type specimen, 210 microns. (Fig. 26, plate XXXVIII.) 



Family Param^cidvE. 



Mouth in either the anterior or the posterior half of the body, pre- 

 ceded by an oblique, somewhat triangular furrow. 



Genus Paramseeium Mull. 



Body oval or elongate, persistent in form but quite flexible. Cuticular 

 surface uniformly ciliated. An oblique, triangular buccal groove leads to 

 the mouth, which is near the center of the ventral side. Contractile 

 vesicles usually two. Macronucleus large, oval or ellipsoidal; two or 

 more micronuclei. Trichocysts abundant. 



Paramecium caudatum Ehr. 



Body elongated, somewhat cigar-shaped, with the posterior half 

 slightly inflated. Rounded at the anterior extremity and pointed pos- 

 teriorly. A triangular buccal groove extends obliquely backward from 

 the anterior extremity to beyond the middle of the body. Mouth located 

 at the posterior end of the buccal grove. Pharynx short, curved, and 

 ciliated. Macronucleus large, centrally located; micronucleus single. 

 Contractile vesicles two, located at about one-third the length of the body 

 from each extremity. Trichocysts abundant and long. 



This is perhaps the most common and most widely known Ciliate, and 

 it can be found in either pond water or vegetable infusions. It varies 

 greatly in size. 



Length of type specimen, 285 microns. (Fig. 25, plate XXXVIII.) 



Paramecium bursaria Ehr. 



Body slightly elongated, about twice as long as broad. Obliquely 

 truncated anteriorly, broadly rounded posteriorly. Buccal groove tri- 

 angular, very wide, extending from the anterior end to beyond the middle 

 of the body. Anus postero-terminal. Two contractile vesicles, one some 

 distance from either end. Macronucleus large, centrally located; micro- 

 nucleus single. Trichocysts abundant and strongly developed. Cyto- 

 plasm usually greenish. 



