INFUSORIA. 161 



ENCHELIA. These Infusoria are found in stagnant 

 water and in decomposing infusions. The body is 

 covered with cilia variously arranged, but there is no 

 integument nor mouth. 



En'chelys nodulosa (PL XI. fig. 26) has a colourless, 

 oblong, irregularly nodular body, coated with very 

 slender radiating cilia, and often exhibits numerous 

 vacuoles. It is frequently found undergoing trans- 

 verse division (fig. 26 a), the body becoming gradually 

 constricted until it separates into two parts, which 

 become perfect animals. 



Alys'cum sal'tans (fig. 39) has an ovoid-oblong, 

 slightly furrowed body, surrounded with radiating 

 cilia, and has a side bundle of long retractile cilia, by 

 means of which it leaps from place to place in the 

 water. 



KERONIA. In this family the body is soft, irregu- 

 larly ciliated, without a special integument, but has 

 an oblique row of vibratile cilia leading to the mouth, 

 and stouter cilia or bristles (setae) on certain parts of 

 the body. The sacculi often contain Diatomacese, &c. 



Oxyt'richa gib'ba (PL XI. fig. 27) has a colourless, 

 oblong body, somewhat expanded in the middle, with 

 setae at the two ends. In the side view (fig. 27 a), 

 the body is seen to be convex above and flattened 

 beneath. 



PARAMEC'INA. The species belonging to this family 

 have a soft, flexible body, which is usually oblong and 

 flattened beneath, with an integument covered regu- 

 larly with pits and rows of cilia. 



Col'poda cucul'lus (PL XI. fig. 30) has a slightly 

 compressed body, ciliated all over, and kidney- shaped 

 or rounded on one side and notched on the other, the 

 surface exhibiting rows of nodules. The mouth is 

 situated at the bottom of the notch. 



Paramecium aurelia (fig. 28) has the body oblong 

 or oblong-ovate, the mouth being placed near the 

 anterior third of its under part. This infusorium is 



p3 



