314 REPORT ON ZOOLOGY, MDCCCXLIV. 



from the proper segments, though in reality a modification of these. The 

 segments have that designation when they can be drawn in or pushed forth 

 at will. The Reporter does not think this mark precise enough to distin- 

 guish the one from the other in every case ; instances often occur where either 

 denomination might be applied with equal justice. The spiracles afford the 

 surest mark, as has been already stated. (Report, 1 843, p. 122.) Neither can 

 he agree with the views of the author respecting the first segment. In the 

 Monograph of the Staphylinidse it is laid down that the first dorsal segment 

 has none corresponding to it on the underside, but Schiodte asserts that 

 every dorsal has its corresponding ventral segment. Anatomically, it is 

 true, a ventral segment may be demonstrated, opposite to the half ring there 

 treated as the first of the back, but it is of no consequence as a segment, 

 and the one which comes after is articulated directly with the breast. 

 Subsequently the Reporter has become convinced by the comparative 

 examination of different families, as well as of the earlier states, that this 

 segment is properly the second, and that the first (like-wise without a con- 

 tinuation on the underside) lies still more forwards, and is in fact the part 

 commonly regarded as the postscutellum of the metathorax, to which the 

 large spiracles belong, treated by all authors, and also in the work last 

 cited, as the spiracles of the metathorax. Although more resembling in size 

 and form the spiracles of the thorax, than those of the other abdominal 

 segments, the consideration of the metamorphosis proves that they are 

 identical with the pair placed in the first segment of the abdomen in the 

 larva.* Accordingly the Coleoptera in general possess two dorsal segments 



* This later view of the learned and philosophical editor of the Archives 

 remains, however, open to discussion. It seems, for instance, fully as 

 reasonable, from the more separated and contrasted forms of the several 

 parts in the perfect insect, to proceed and identify their counterparts in the 

 larva, where the distinction of thorax and abdomen is usually less marked, 

 as it is to assume first the line of division (arbitrary by comparison) in the 

 latter, and thence to impose upon the former denominations at variance, it 

 may be, with the position and apparent office of the parts which they are 

 here employed to denote. If in some insects in the perfect state (as 

 Orthoptera) it may seem allowable to assign the segment in question as well 

 to the abdomen as the thorax, yet in the greater number, but particularly in 

 the small-waisted Hymenoptera, its intimate connexion with the thorax is 

 evident, and no describer has ever been at fault in regard to it. To Ne win a n 

 the merit belongs of having pointedly called attention to the mutual 

 relation and characteristic importance of this and the following segment, to 

 which he gave respectively the names of propodeon and podeou ; terms 

 which might stand, unless considerations of harmony in the description of 

 1 he thorax should recommend for the former a name framed in accordance 



