Thorax in winged Insects. 167 



Mr. Kirby has most correctly observed, as well as that it is the evanes- 

 cence at hist of this small membrane and the junction of the sides of the 

 antepectus, or more accurately speaking, the connection of the eplmera 

 of the prothorax, which forms the singular necks of Xiphydria and 

 FoEiius. These two Hymenopterous genera, so far from being nearest to 

 Coleoptera in structure of the thorax, are the farthest from them, as they 

 present no vestige of the preescutum and scutum of the prothorax what- 

 ever. 



Mr. Kirby, with his usual acuteness observes, that there is no meso- 

 thoracic prcescutum, or as he terms it, no prophragma in front of the 

 collare, (which, by the way, there ought to be, on the supposition of its 

 belonging to the mesothorax,) but one behind it. This is an incontro- 

 vertible argument to shew that the collare belongs to the prothorax.* I 

 conceive the collare therefore to represent the third piece of the tergum 

 of the prothorax in Lociista, which piece is perhaps evanescent in the 

 generality of Coleoptera. This view of the matter will satisfactorily ex- 

 plain all the difficulties which have been so ably brought together in the 

 Introduction to Entomology, and the collare shall hereafter be always 

 termed by me the scutellmn of the prothorax.f 



But to understand better what precedes, and to have some notion of 

 the construction of an Hymenopterous insect, let us take a Polistes.^ 



* I know not exactly how Mr, Kirby would argue, and scarcely what he 

 alludes to, when he says that the collare is not separated in any loaxj from the 

 mesothorax in a " Neuter Mutilla." He forgets that in Apterous Hymennptera 

 all the pieces of the thorax are sometimes soldered together into one mass. His 

 argument drawn from Xylncopa proves nothing more than that, in this genus 

 of Bees, the narrow collare is excessively developed laterally, as in other Hy 

 menopteia it is developed longitudinally. 



t According to M. Audouin it is the scutum of the prothorax. 



X My insect is perhaps the most common "Wasp in Cuba, where it builds a 

 nest of 7 or 8 vertical cells, under the eaves of houses, or any place where it 

 may be sheltered from rain. Its nest is composed of the ordinary papyraceous 

 substance, and of the form and size of Tab. vi. fg. xi. It is consequently 

 rather a solitary wasp, rarely more than three perfect insects being seen 

 about a nest. But, on the other hand, in a convenient situation, these 

 little nests may be seen studded together in great frequency. As far as 

 the vague descriptions of Fabricius will allow me to judge I believe it to be 



