MANUAL OF NATURAL HISTORY. 371 



2. Family. — Loricated Bell-Animalcules (Ophry- 



diidse). Animal loricated ; solitary or ag- 

 gregated ; with a shell. 



II. SUB-ORDER. — Enantiotretans (Enantiotreta). 



Mouth and anus terminal, and opposite ; repro- 

 duction by transverse division. 



3. Family. — Rolling -Animalcules (Enchelidso). 



"Without a shell. 



4. Family. — Box- Animalcules (Colepidse). Lori- 



cated, or furnished with a shell. 



III. SUB-ORDER.— Allotretans (Allotreta). 



Mouth and anus terminal and opposite ; repro- 

 duction by longitudinal and transverse division. 



5. Family. — Neck- Animalcules (Tracheliidse). Anal 



opening alone terminal ; without a shell. 



6. Family. — Swan-Animalcules (Trachelocercidae). 



Oral opening only terminal ; without a shell. 



7. Family. — Shield - Animalcules (Aspidiscidao). 



Anal opening only terminal ; with a shell. 



IV. SUB-ORDER.— Katotkvtaxs (Katotreta). 



Mouth and anus not terminal; reproduction by 

 longitudinal and transverse division. 



8. Family. — Breast - Animalcules (Colpodidse). 



Without a shell ; neither opening terminal. 



9. Family. — Hackle - Animalcules (Oxytrichidae). 



Without a shell; with vibrating cilia, and 

 with non-vibrating styles or uncini. 



10. Family.— Boat-Animalcules (EuplotidsB). With 



a shell ; neither orifice terminal. 



