FLESH-FLIES. 207 



next day after their arrival, August 13, these eggs hatched. The young 

 larvae were of the same size and about the same shape as the egg. They 

 immediately made their way into the cotton-worm chrysalis, to which 

 the leaf was attached. They were seven in number. In four days they 

 had demolished the chrysalis and increased greatly in size. Having 

 finished this chrysalis, they emerged and crawled about, evidently search- 

 ing for more food. Another Aletia pupa was furnished, which they de- 

 stroyed in less than three days. In this way some five or six pupae were 

 eaten out by them. On the 20th of August they appeared nearly full- 

 grown, and on the 23d all but one transformed to puparia only ten 

 days having elapsed from the time of birth. 



The full-grown larva was about a half inch (12.5 mm ) in length, 0.119 

 inch (3 mm ) in width at the posterior end of the body, which is truncated. 

 From this point it tapers gradually down to the head, which ends in a 

 nearly sharp point. Its color is white. But twelve segments to the 

 body are discernible, the head being entractile within the first thoracic 

 segment. At the juncture of the segments there is a projecting rough- 

 ness around the body, more prominent, however, on the lower side, for 

 purposes of locomotion. The larva, then, corresponds pretty well with 

 Professor Kiley's general statements concerning Sarcopliaga larvae just 

 quoted, but the puparium seems intermediate between that of Sarco- 

 pliaga and Tachina. It will be remembered that one of these distinc- 

 tions which he lays down as between Tachina and Sarcophaga is that the 

 puparium of the former is "quite 

 uniformly rounded at each end," 

 while that of the latter is " trun- 

 cate behind and more tapering 

 in front, where the prothoracic 

 spiracles show, as they never do 

 in Tachina." In the present in- 

 stance, however, the puparia, as 

 shown in the figure, were much 

 more nearly uniformly rounded 

 at the ends than is customary 

 with Sarcophaga, and the prothoraeic spiracles were represented by thf 

 most insignificant tubercles. 



August 28, or five days after entering the pupa state, two flies emerged, 

 and August 29 the other four issued. They showed the characteristic 

 plumed antennal bristles of the Sarcophagidae, but differed in wing vena- 

 tion from any specimens of Sarcophagidae or Tachiniidae which I have 

 seen. In general appearance these flies much resemble the sarraceniae, 

 but are rather smaller. The six specimens bred diflfer among themselves 

 strangely in regard to the width of the space between the eyes, as in 

 three of them it equals one-third the width of the head, and in the others 

 it. is the merest line. 



It is impossible to say from the experience had with them whether this 



