ZOOLOGY» 

 ORDER V. 



INFUSORIA, 



The so-bjects of tliis order are all exceedingly minute, beiDg 

 for the most part ooly discoYerable by the Microscope ; 

 they are found in stagnaot waters, vegetable infusions, and 

 are generally known by the term Animalcules. They are 

 divisible into three families : * with external organs : "^'^'•wiih' 

 oMi external organs^ flattened : * without external organs^ 

 round. 



1. Brachionus. Body contractile, covered with a shelly 



and furnished at the head v/ith ciliated rotatory organs^ 



2. Vorticella. 1^0% contractile, naked, and furnished witli 



ciliated ro^rt^on/ or^«?25 ; this genus is divided into three 

 families; * animal affixed on a s'^em or pedicle; 

 animal tailed ; animal without stem or taiL 



Most of this genus are so minute, as not to be discover- 

 able without the aid of a lens. 



S. Trichoda. Animal minute, pellucid, hairy or horned ; 

 there are two families in this genus, the one h airy , thQ 

 other with horn-like processes. They are all micro- 

 scopic objects, and invisible without the assistance of 

 glasses. 



4. Cercaria. Animal an visible to the naked eye ; pellucid 

 and tailjd. 



