Pipunculus. 



13 



or semicylindrical, sometimes a little more flattened, the tergites 

 form by far the largest part and are arched, while the ventrites 

 are plane and somewhat narrow; in the female abdomen is sometimes 

 a httle broader behind than at the base. In the male abdomen has 

 five not transformed dorsal segments of about equal length except 

 the fifth, which is the longest; in some species the fifth segment has 

 the hind margin a little imsymmetrical, the segment being a little 

 longer on the right than on the left side (fig. 4). On the ventral side 



Fig. 6. P. Thomsoni S \ ab- 

 domen from below; 6, sixth 

 segment with its ventrite, 

 7, seventh segment, 8, eighth 

 segment with its apical im- 

 pression, 9, hypopygium. 



(^, 



Fig. 7. P. TIwmsoni ^ ; abdomen 

 from below; eighth segment and 

 hypopygium removed ; 6, sixth seg- 

 ment with its ventrite, 7, seventh 

 segment with its vertical ventrite, 

 6\, the narrow, here quite hidden, 

 dorsal part of the sixth segment. 



there are only foiir not transformed segments, the fifth being quite 

 short and not or slightly chitinized. After the normal segments foUow 

 those which are transformed and constitute the exterior genitalia. 

 The genitalia apparently form a large, roundish or conical knob at 

 the end of abdomen with a smaller or larger, sometimes nearly or 

 quite wanting apical membraneous impression (fig. 5). On a closer 

 examination we find on the left side below next to the large fifth 

 dorsal segment a very small sixth segment, it is triangular and lies at 

 the left hing corner of the fifth, (figs. 6, 7) but in reality it is present 



