326 THE ENTOMOLOGIST. 



to the larvae that made the cocoons. They are of a highly 

 anomalous nature, and agree in certain respects with the pupa 

 of Micropteryx, whose discovery was recently made by Dr. Chap- 

 raan, though very different in other points. There are these dis- 

 tinctions : 1, there are no free mandibles ; 2, the ventral aspect 

 is that of an anomalous pupa incompleta of Chapman, while 

 the dorsal aspect is that of the Neuroptera, either of Hemerobiid 

 or Trichopterous kind, but highly peculiar. The appendages 

 on the ventral aspect are imperfectly fastened to the body, but 

 the -wings extend quite to the extremity of the body, and are 

 free, as to their edges, on the dorsal aspect. The front of this 

 soft imperfectly chitinised pupa bears a hard projecting chisel, 

 which differs from all the rest of the pupal surface in that, 

 instead of being pallid and membranous, it is dark, hard, and 

 strongly chitinised. The dorsal aspect of the abdomen is sui 

 generis, for though soft it is thrown into several series of ridges 

 or folds, each of which bears a projecting, chitinous, acuminate 

 tubercle ; the structure of this dorsal part of the abdomen in- 

 dicates great mobility of the segments on this aspect of the 

 body. There are seven of the rows of ridges, 8-12 in each row ; 

 the longest and strongest are curved backwards. The most 

 remarkable of all the features of this pupa is that the pleura 

 of the abdomen are developed as large free flaps, which bear 

 numerous long and strong setae. There are also a few long setae 

 projecting from other parts of the body. 



With these data we can make a fair guess at the modus 

 operandi of the insect. This little pupa is shut in a remarkably 

 hard thick cocoon without any orifice, and it has to get out. 

 Nature has not provided it with caustic potash for the purpose, 

 but has endowed it with a mechanism of complex perfection to 

 accomplish this little object. On the front of the head it has a 

 sharp chisel edge, and with this it has to cut through the pot- 

 tery ; contracting itself to the utmost in the posterior part of 

 the cocoon, and retaining itself in this position by the hooks on 

 the' mobile part of the body, it is in a condition of elastic tension 

 in consequence of the other side of the body being so differently 

 formed and immobile ; therefore, releasing the hold of the hooks, 

 the pupa is discharged forwards, and the chisel piece strikes the 

 front part of the cocoon ; repeating this an enormous number of 

 times a circle may be gradually inscribed on the inside of the far 

 end of the cocoon, which gives way when sufficiently weakened, 

 and the insect becomes free. In both the specimens the inside of 

 the cocoon is about half-cut through ; either this is done as the 

 result of a prolonged series of wriggles, or of shocks such as I 

 have described. It is by no means improbable that the early part 

 of the performance is carving the groove by wriggling, the later 

 part knocking it off by jumping against it. The pleural setae are 

 doubtless the sense organs that co-ordinate the movements. 



