162 PROTOZOA. 



of comparatively large size, and is often found in 

 immense numbers in infusions, which it renders milky. 

 It is admirably adapted for showing the sacculi, which 

 are easily tilled with indigo. The body exhibits two 

 remarkable stellate organs, consisting of a central 

 contractile vesicle, surrounded by several radiately 

 placed oval vesicles, which may be seen to contract 

 and dilate with great regularity. The body is coated 

 with very fine cilia. 



Amphilep'tusfasciola (fig. 29) is furnished with an 

 elongate fusiform or lanceolate flattened body, with a 

 lateral oblique mouth. 



Chitodon cucul'lulus (fig. 37) has an oblong thin 

 body, irregularly wavy on the sides ; the mouth being 

 situated obliquely in front of the middle, and fur- 

 nished with a cylinder of parallel rod-like teeth. 



Nas'sula eVegans (fig. 31) has the body ovoid or 

 oblong, becoming globular when contracted, the 

 mouth being furnished with teeth as in Chilodon. It 

 is often found among Oscillatorise. 



URCEOLARNA. Vorticel'la convalldria (PI. XI. fig. 

 34) is very commonly met with in decomposing infu- 

 sions. The bell-shaped body is fixed at the end of a 

 slender stalk, which is often seen to be extended and 

 then suddenly contracted into a spiral (fig. 34 a). 

 The cilia are arranged around a raised rim at the 

 front of the body, and extend down a fissure leading 

 to the mouth. The sacculi of this infusorium may 

 be readily filled with indigo. The process of longi- 

 tudinal division may also often be observed, taking 

 about an hour for its completion ; and when the new 

 individual is about to separate from the parent, a ring 

 of cilia may be noticed to have sprung up around the 

 base (fig. 36). The encysting process is also often 

 visible, the cilia disappearing, and the body becoming 

 globular and secreting a cyst around it ; after a time 

 the contents become resolved into a number of em- 

 bryos, which escape by the bursting of the cyst 



