THE CHALCIDOID GENUS PEEILAMPUS. 47 



change quite materially. The mouth parts are in this stage situated 

 in a triangular basinlike depression which is bounded on two sides and 

 parts of the third by a strong chitinous carina or rim. Besides the 

 mandibles there are two bulblike appendages just beneath, which 

 are ])robably homologous to the maxilla3 of the adult. Immediately 

 above the oral opening are situated two large rounded elevations 

 which may be called larval antennae. The segments forming the 

 head are now separated by a more or less distinct neck from the 

 remaining segments and are bent beneath them with face downward, 

 as in the second stage. The first two thoracic segments are each 

 provided laterally with a raised tubercle at about the middle of the 

 segment, viewed from the side, antl just above this tubercle is another 

 more or less distinct one, one also occurring on the third thoracic 

 segment in a corresponding location. The next three segments each 

 bear a pair of much larger tubercles or projections 

 which give the larva a very unusual appearance. /^"""^^ 



These tubercles, if they may be called such, corre- i ^. 



spond to those described and figured by Dr. Wheeler }- 

 as occurring in Orasema, but are somewhat differ- [ 

 ently arranged. Just posterior to these there oc- ^ ,^^ 

 curs an abrupt declivity, the segments becoming - ^i"^ - 'p 

 much smaller toward the posterior end of the ^f /I ''y 

 larva. Beneath, the larva is smooth and free from v^^^^ 



constrictions, but the segmental sutures are visible to ^s^^ 



some extent. Dorsally through a transparent me- XaJlk:fr'TZ 

 dian line formed by a break in the corpus adiposum larva. Greatly en- 

 may be seen a large number of white urate masses, ^"^^^ ' "^'^"^^ '^ 

 -which pulsate slowly back and forth as the larva feeds. The 

 tracheal system is rather conspicuous and is of the normal holo- 

 pneustic type. 



PUPATION. 



(Figs. 28, 29.) 



As soon as the larva is full fed, pupation takes place. The meco- 

 nium is discharged, leaving the larva scarcely more than half its 

 former bulk, and creamy white instead of translucent gray-white 

 in color. Beneath the larval sldn the imaginal appendages and the 

 head gradually appear, and the tubercles so characteristic of the 

 larva become less conspicuous. Finally the larval skin is discarded, 

 and the pupa assumes its own distinctive shape. 



The pupa is short and robust, corresponding very closely, of course, 

 to the form of the adult. The abdomen bears five or six transverse 

 carime or ridges, one for each segment, which are interrupted on the 

 tlisk. These are very similar to those occurring on the ant parasite 

 Orasema viridis, but differ in that they are not continuous dorsally 



