BY H. A. BAYLIS. 



311 



rounded papilliform cuticular structures, possibly representing 

 the denticles found in some species of Physaloptera, but these 

 are not constant, and no true denticles have been observed. 



The tail of the male is 1.7 mm. in length. The caudal end 

 (fig. 6) is provided with very strongly developed lateral alae, 

 forming a "bursa" of the type usual in the genus, and 

 continuous across the ventral surface some distance in front of 

 the anus. The "bursa" is voluminous, vesicular and much 

 folded. Its ventral surface is provided with the usual longi- 

 tudinal rows of papilliform cuticular processes. In the 

 mid-ventral region these processes are simple and button-like, 

 but in the more 

 lateral rows they 

 become gradual- 

 ly more elonga- 

 ted, sharp and 

 claw-Uke. The 

 "burs a" i s 

 somewhat asym- 

 metrical, the 

 lateral ala of the 

 right side ex- 

 tending an- 

 teriorly some- 

 what further 

 than that of the 

 left. The usual 

 four pairs of 

 long-stalked la- 

 teral papillae are 

 present. Imme- 

 diately behind 

 the most pos- 

 terior of these, 

 and a little near- 

 er to the mid- 

 ventral line, is 

 another pair 

 of papillae with 

 moderately long 

 peduncles. 

 About midway 

 between these and the tip of the tail there are two pairs of 

 sessile subventral papillae, of which the more posterior is 



Fig. 6. 



Physaloptera mydai. Caudal end of 

 male; ventral view. 



