smith: infusoria of Kansas. 169 



long and conspicuous. Macronucleus band-like. Two contractile vac- 

 uoles. 



This is a very common species in infusions of hay and leaves. 



Length of type specimen, 95 microns. (Fig. 64, plate XLVI.) 



Subfamily Vorticellin^e. 



Forms usually cup- or bell-shaped, without a permanent secondary 

 wreath of cilia. Contractile peristomal fold present, enabling .the ani- 

 mal to enclose the peristome. 



Genus Scyphidia Lachman. 



Forms solitary, unattached. Body elongated, pyriform, highly con- 

 tractile. Posterior end with an organ of attachment. Surface smooth 

 or striated. Mouth anterior, eccentric. Pharynx distinct. An elevated 

 ciliary disc, surrounded by a fringe or adoral cilia, descends into the oral 

 aperture. 



Scyphidia inclinans D'Udk. 



Body highly contractile, somewhat pyriform, slightly widest centrally, 

 more than twice as long as broad. Posterior end narrow and stalk-like. 

 Ciliary disc elevated obliquely. Pharynx conspicuous, extending to the 

 middle of the body. Cuticular surface smooth. Macronucleus band-like. 

 Contractile vacuole single, located near the pharynx and just beneath the 

 peristome border. Body slightly bent to one side when not fully extended. 



Found in pond water among alga?. 



Length of type specimen, not fully extended, 60 microns. (Fig. 63, 

 plate XLVI.) 



Genus Vorticella Linnaeus. 



Body usually cup- or bell-shaped, attached posteriorly to an un- 

 branched, contractile stalk. Adoral mechanism consisting of an elevated 

 ciliary disc, encircled by an adoral wreath of large, strong cilia which 

 descends to the mouth. Mouth eccentric. Pharynx usually conspicuous, 

 tube-like. Contractile vacuole single or double, located near the pharynx. 

 Macronucleus band-like, curved. Cuticular surface either smooth or 

 transversely striated. Individuals often social, never colonial. 



The classification of the various species of Vorticella is very difficult 

 because of the slight amount of variation between species, the ease with 

 which the individuals vary in contour, and the great number of species 

 based upon minor differences. There is very little to build upon in classi- 

 fication. Calkins believes that the 66 species enumerated by Stokes and 

 the several new species added since his work might safely be reduced to 

 12 or 15 species, and this is perhaps true. I do not, therefore, expect 

 every one to agree with me in my classification of Vorticella. 



Vorticella gracilis Duj. 



Body conical, about twice as long as broad. Anterior margin slightly 

 everted. Contractile vacuole single. Cuticular surface smooth. Body 

 transparent. Stalk slender, about one and a half times the length of the 

 body. Length of type specimen 70 microns. (Fig. 53, plate XLV.) 



