614 Mr. D. Sharp and Mr. F. Muir 07i the Comparative 



We have omitted from our tentative tables certain 

 families that we have examined, e.g. Trichopterygidae and 

 Discolomidae, but we have been somewhat inconsistent, 

 inasmuch as we have inserted others that are perhaps 

 quite as doubtful. Any one who will examine such forms 

 as Gerylon will appreciate the difficulty as to making a 

 correct conclusion as to the morphology of the aedeagus 

 in these exceptional cases ; the examination of a series of 

 allied forms is often imperative before coming to a positive 

 conclusion. 



We must also reiterate here what we have said else- 

 where as to the " Spicule." This is scarcely touched on 

 by us, because it would have involved us in the considera- 

 tion of the number of abdominal segments ; but we 

 recognise the importance of the subject. A comparative 

 study of this sclerite, together with the terminal body 

 segments, is necessary before a final decision can be 

 reached for taxonomical purposes. 



At present we are disposed to adopt eight series. We 

 have considered the possible relations of these series in 

 the section on phylogeny. 



(1) Byrrhoidea. 



Under this name we include twenty or thirty families. 

 The complex is of considerable importance, as it is possible 

 to consider that we are here in the presence of the more 

 primitive of the conditions of the Coleopterous genital 

 tube, so far as existing forms are concerned. We use this 

 qualification because the structures are very far from 

 being truly primitive. The peculiarities of this complex 

 may be thus summarised, viz. : A median lobe, bearing 

 (as in other cases) the orifice of the duct, and on each side 

 of it a lateral lobe, the sclerites being intimately connected 

 with a basal-piece. The tegmen is thus very complete, 

 and the relation between it and the median lobe is one 

 that allows of very little movement backwards and for- 

 wards of the median lobe independent of the tegmen. 

 This distinguishes the famiUes from the Cucujoidea. 

 Moreover, the sac is never highly specialised, in many 

 cases is scarcely differentiated from the duct. 



The Buprestidae are peculiar, possessing a remarkable 

 coadaptation between the inner aspects of the lateral lobes 

 and the median lobe, which permits the median lobe to 

 glide backwards and forwards in the slots of the lateral 



