388 



The following are the characters of the re- 

 spective species : — 



F. bancrofti. — Males and females found to- 

 gether in lymphatics. 



? I. Length, eighty-five to one hundred and 

 fifty mm. 



2. Distinct neck ; one-third width of body. 



3. Body plain, tapering somewhat abruptly 

 to neck, and tapering towards tail. 



4. Cuticle with striations. 



5. Tail ends bluntly, and has a small de- 

 pression, surrounded by two small lips. 



6. Mouth simple, minute, terminal. 



7. Ova twenty-five to thirty-eight m by 

 fifteen m- 



8. Anus ventral opening on summit of a 

 bilobed papilla. 



$ I. Length, eighty mm. 



2. Body cylindrical, tapering to tail. No 

 neck. 



3. Mouth circular, simple, terminal. 



4. Cloaca ventral, four pairs pre-anal, four 

 post-anal, papillae (Manson doubts the presence 

 of these). Two unequal spicules. 



5. Genital tube simple. Oesophagus thick- 

 walled. 



6. Tail vine-tendril like, with one or two 

 spirals. 



F. Persians : 

 $ I. Length, seventy to eighty mm. 



2. Neck longer than F. bancrofti. 



3. Body without markings. 



4. Tail incurvated. Tip of tail mitred. This 

 is characteristic of this species. 



5. Mouth minute, simple. 



