INFUSORIA. 



iSS 



cular. It is always adherent to some submerged ob- 

 ject by the broad flat side, the opposite or upper sur- 

 face being convex. The opening, through which the 

 animal extends itself, as in Vaginicola, is at one end, 

 and is often prolonged into a short neck. The figure 

 shows a side view with the animal extended. 



When young the lorica is color- 

 less, but it soon changes to a 

 deep brown, often becoming so 

 opaque that the body of the Infu- 

 sorium cannot be seen through 

 its walls. 



The body itself is usually color- ^.^ „..-Piatycoia. y 

 less; it is attached by its tip to ^^ 



the side opposite the mouth of the lorica. When 

 frightened it darts back into the sheath as Vaginicola 

 does. Two animals are not seldom found in one 

 lorica. It is not uncommon on Ceratophyllum and 

 on other aquatic plants. 



8. CoTHtJRNIA (Fig. 113). 



The observer may at first mistake this for a small 

 Vaginicola, as the loricse somewhat resemble each 

 other in shape; but Coihiirnia can always be distin- 

 guished by the little stem or foot-stalk that 

 lifts it a short distance from the plant to 

 which it is attached. This foot-stalk in 

 some species is very short, and must be 

 especially looked for; in others it is some- 

 what conspicuous. The lorica is vase- 

 shaped, often with the sides variously 

 curved. It changes to a brown color as 

 it grows old. 

 • The body of the enclosed Infusorium is _coth"rniaP' 



