MANUAL OF NATUKAL HISTOEY. 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 (Enchelidae). 



Without a shell. 



4. FAMILY. Box- Animalcules (ColepidsB). Lori- 



cated, or furnished with a shell. 



III. SUB-ORDER. ALLOTKETANS (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 (Trachelocercidse). 



Oral opening only terminal ; without a shell. 



7. FAMILY. Shield - Animalcules (Aspidiscidae). 



Anal opening only terminal ; with a shell. 



IV. SUB-ORDER. KATOTRETANS (Katotreta). 



Mouth and anus not terminal; reproduction by 

 longitudinal and transverse division. 



8. FAMILY. Breast - Animalcules (Colpodidas). 



Without a shell ; neither opening terminal. 



9. FAMILY. Hackle - Animalcules (Oxytrichidse). 



Without a shell; with vibrating cilia, and 

 with non-vibrating styles or uncini 



10. FAMILY. Boat-Animalcules (Euplotidse). With 



a shell ; neither orifice terminal. 



