288 Mr. S. S. Saunders on the Habits of the 



region of the larva. These reniform appendages, vvliite in the first 

 instance like the rest of the larva, but which assume a deep 

 chestnut brown as the latter approaches its period of pupa meta- 

 morphosis, exercise important functions in connection with the 

 tracheae as organs of respiration, supplies of air being obtained 

 from the interior of th.e abdomen of the Pumpilus, through tlie 

 medium of the perforated surface of the rugosities with which 

 these appendages are invested. 



The larva subsequently contracts into a compact oval form, the 

 pupa-case so constituted being of inflexible consistency and of an 

 uniform deep piceous hue ; in which condition it remains until 

 the exit of the perfect Conops towards the end of June in the fol- 

 lowing year. The anterior extremity of this pupa-case presents 

 a somewhat flattened top, having impressed thereon two concentric 

 rings, with a central depression corresponding, as it would seem, 

 with the original buccal orifice, and surrounded with a distinct 

 convex margin ; these rings obviously representing the aforesaid 

 retractile tubular segments, and suggesting the resemblance to a 

 closed opera-glass ! This flattened extremity is connected at its 

 base with a lateral ridge, forming a longitudinal carinated division 

 of the cap of the pupa-case, which is thrown oft' as an operculum 

 on the liberation of the imago. 



It is worthy of notice that these pupa-cases are turned inversely 

 to the dorsal and ventral region of the Ponipilus ; the parasite 

 being reversed, its head deflexed below the lateral carinae in the 

 direction of the dorsum of the Ponipilus, and the reniform appen- 

 dages having their more dilated portion recumbent in the same 

 direction. This position of the Conops pupa would seem to be the 

 natural result of the conformation of the abdomen in the Pomjulus : 

 the contracted base of which, connecting with the thorax, is on the 

 same plane as the ventral region ; so that the Conops larva would 

 naturally turn in the direction of the vaulted recess of the dorsal 

 region, on preparing for its coarctate pupa-metamorphosis. • 



The exit of the perfect Conops is effected by the separation of 

 the first and second abdominal segments of its victim ; and when 

 such disjunction cannot readily be accomplished, as in the case of 

 specimens desiccated for the cabinet, the Cunops remains without 

 the means of extricating itself, imprisoned in the abdominal cavity. 

 Unrestricted however on such occasions by its pupa-position, the 

 perfect Conops, when encountering obstacles to its egress, turns 

 within the pupa-case in any required direction; but under ordinary 

 circumstances it may be assumed that the Pompilus, on the termi- 



