PARASITES OF ELEPHANTS, 



263 



the anterior part of the oesophagus from the level of the nerve 

 collar to the mouth collar. They are placed in the submedian 

 planes. Each has a long, thick duct, which can be traced easily 

 to the level of the groove separating the mouth collar from the 

 body. As has been mentioned already, probably these ducts 

 open on the top of the submedian head papillte. Their contents 

 are big granules in the centre, surrounded by fine granules which 

 also fill the ducts. 



CEsophagus. — There is a shallow oesophageal funnel sur- 

 rounded hy a thick chitinous Avail. The lumen of the 

 anterior -07 mm. of the oesophagus is ridged, having a 

 plumose appearance similar to that seen in P. africana. The 

 rest of the lumen of the oesophagus is "4 mm. in length and 



Text-figure 61. 



WO/j 



Memphisia aziza Khalil. Lateral view of cephalic portion of body. 



•14 mm. maximum diameter. It is slightly constricted at 

 the site of the nerve collar. The caudal termination of the 

 oesophagus projects into the lumen of the chyle intestine, 

 forming three small lobes. 



Chyle intestine. — The cellular wall of the chyle intestine is 

 pigmented throughout its entire course. It pursues a nearly 

 straight course. 



Rectum. — This is a short tubular structure, Avith chitinous 

 wall sharply demarcated from the rest of the intestine. 



Excretory system. — The excretory vesicle is large and oblong. 

 The short excretory ducts open in the median ventral line 

 •72 mm. from the cephalic extremity. 



