APPENDIX. 589 



ing several dried bees, ichneumons, &c., in which the collare always remained 

 attached to the thorax, when the fore-feet were pulled off, and never came off 

 along with them. But I was fully convinced from a large female ant which I 

 took a few days ago alive. In making efforts to release itself, the fore-feet were 

 pulled to a considerable distance from the collare, to which they were attached 

 above merely by a dilatable membrane ; but the collare was immoveably fixed 

 to the dorsum, and though there is a suture between them, it was with difficulty 

 I could separate them by dissection. Another observation which proves that 

 the collare is no part of the thorax, is, that putting a pin under it, and endea- 

 vouring to push it off, the wings were strongly moved, so that their muscles must 

 be attached to the under side of it. Now we know that the wings in Coleoptera 

 have no connection with the thorax. I am now persuaded that the upper side 

 of that part in Hymenoptera analogous to the thorax in Coleoptera is rarely or 

 never visible, the part itself being extremely thin, and wholly concealed by the 

 collare. The question then comes ' What is the collare analogous to ? ' and 

 here I confess that I have not altogether satisfied myself, but must apply to 

 your more extensive acquaintance with the order. Illiger says your tubercula 

 are analogous to the scapularia of Coleoptera, and I am inclined to think 

 rightly. If so, as the scapularia seem in general to be connate with the collare, 

 or separated from it by an apparent suture, probably this part is analogous to a 

 concealed vertical piece which I find at the base of the scutellum in a large 

 foreign Geotrupes, and which you will easily see on dissection. Now, if this 

 supposition be correct, then taking this Geotrupes for our Coleopterous instance, 

 we shall see in it pretty clearly the parts to be seen in Hymenoptera ( Vespa 

 Crabro, for instance). Having separated the postpectus in the Geotrupes, we 

 see at the base of the scutellum, first a vertical part forming a right angle with 

 it. This I conceive to answer to the collare, which in Vespa is deflexed nearly 

 in the same manner. The tubercula in Vespa, or lateral triangular parts of the 

 collare, I conceive to answer to the scapularia in Geotrupes. (I must here ob- 

 serve, in order to obviate the objection that the scapularia are not placed so 

 high up, that the scapulare is not merely the triangular white part which I 

 mentioned to you as being present in Coccinella 7 punctata, but includes also 

 another part at the base of that, the base of the true scapulare, which is 

 divided into two portions by an apparent, not real, suture, being in a line 

 with the base of the peristethium.*) Next in the Geotrupes comes the con- 

 cealed, horny, horizontal base of the scutellum ; doubtless, as we have always 

 considered it, equivalent to our dorsum in Hymenoptera, and the exposed or 

 true scutellum is equivalent to your scutellum in Hymenoptera. Now comes 

 in Vespa between the scutellum and your quondam metathorax, another trans- 

 verse piece, which, as you have not named in Apis, I suppose is not found in 

 them. To what in Coleoptera is this analogous ? Here, again, our Geotrupes 

 comes into play. If you take off" the scutellum, you will find concealed by 

 it at the base of the channelled lumbi, with which it forms a right angle, 

 a curious vertical, square, horny plate. This seems to me analogous to the- 

 above intermediate part in Vespa. Lastly, in Vespa comes your quondam 

 metathorax, doubtless analogous to Illiger's interscapulium, or the channelled 

 part in Coleoptera, covered by the base of the elytra. So much for the upper 

 side. Next as to the under side of the postpectus in Vespa. The large 

 dilated part between the fore and middle feet must be analogous to the peri- 

 stethium in beetles. The sides of this part seem to form your pleura. The 

 scapularia I have mentioned before. The mesostethium must be a very small 

 part between the four hind legs, and between the sides of this and the 

 peristethium lie two smaller parts, which I conjecture to be our hypochondria. 

 Thus I have made out, in one way or other, all the same parts in Hyme- 

 noptera which are found in Coleoptera ; and vice versa. You must decide 



