1028 



MR. E. J. OKTLEPP ON THIS 



of the two oesophageal paints. The excretory pore is situated 

 about 50 fj, further back. 



The lips are large and somewhat triangular in side view, and 

 each carries on its apex a large triangular tooth. Immediately 

 internal to it there is a slightly larger but membranous tooth, 

 whose free extremity is tripartite. No lateral teeth are present. 

 Each lip bears on its outer surface two conspicuous papillse. 



The oesophagus is long, and in the female it is about l/7th, in 

 the male slightly more or slightly less than l/5th of the body- 

 length. Its anterior region is differentiated into a short muscular 

 portion, about 400 //. long in fully-grown specimens and slightly 

 thinner than the rest of the oesophagus ; the large nerve ring 

 encircles it in its posterior quarter. 



Text-figure 11. 



Fhysalo]ptera retusa Rud. 

 A = Ventral view of cephalic extremity. 

 B = External aspect of median teeth. 



Female. 



The largest female measured 45 mm. long, and 1*2 mm. broad 

 in the middle ; fully mature females varied in size from 20 mm. 

 upwards. The body is rather robust, tapering only slightly 

 towards both ends ; the tail, however, is sharply set off from the 

 body, and is relatively short and slender ; it forms on an average 

 l/107th of the total body-length, and its caudal pores are situated 

 in its posterior third. 



The vulva opens on a level with the general surface, and is 

 situated some distance behind the end of the oesophagus. Its 

 position varies slightly in diff"erent individuals, but in general it 

 is seen at the junction of the 1st and 2nd quarters of the body. 

 It leads in the largest females into a relatively short and thick- 



