56 PLATE XXV. 



be extracted except by making an incifion through the outer bark. 

 The larva is of a pale yellowifh colour, with the head yellow. In 

 June, early in the morning, or in the evening, the pupa is feen 

 iffuing through the bark from a perforation in the trunk, which the 

 larva had previoufly formed at the diftance of fix or eight inches, 

 or even more from the bottom of its recefs. For the purpofe of 

 facilitating the paffage of this pupa to the aperture of the cell Na- 

 ture has furnifhed every fegment with a double row of fharp teeth, 

 or fpines, by means of which it firmly attaches itfelf to the fides of 

 the cavity, and by repeated exertion gradually attains the entrance 

 of its prifon. When thus far extricated, the anterior part of the 

 pupa is protruded, while the lower, befet with little teeth, re- 

 mains in the cavity ; in this pofture the upper part burfts afunder 

 with violence, and the perfect infe£t rufhes forth, leaving the fliell 

 of the pupa flicking at the entrance of its cell. 



This is a curious infecl:, and as it has been obferved is rarely found 

 except in Effex. 



There is another infect of the Sefia, or tranfparent winged tribe of 

 Sphinges, that differs from the prefent fubjecl: only in a few parti- 

 culars, yet may eafily be diftinguifhed by a crefcent of yellow on 

 the fore-part of the thorax, and is thence entitled the Lunar Hornet 

 Sphinx. A drawing of the latter, with the larva, has been prefented 

 to the Linnaean Society ; and will be alfo found in a future part of 

 this work. 



The infeft now under confideration is arranged in many cabinets 

 under the title of Sphinx Vefpiformis ; but it is not the Sphinx Vef- 

 piformis of Linnaeus ; the latter, in the pofTeffion of Dr. Smith, we 

 have feen, and it fcarcely exceeds half the fize of the prefent fubjecl:. 



PLATE 



