CLASSIFICATION OF COLEOPTERA. 217 



cence of the gular sutures and the disappearance of the sutures 

 between the pleurte and the sternum and notum of the pro- 

 thorax — are characteristic of the group as a whole and confined 

 to that group. But even as regards those two characters there 

 are exceptions within the group. From my own observations I find 

 that the gular sutures are quite distinct and as wide apart in the 

 OxycorinidfB as they are in many families outside the group ; they 

 are rather widely separated also in the genns Rhinomacer ; and again 

 in some Platypodinse, as' for example, Crossotarsus, they are, though 

 strongly convergent behind, quite separate right up to the hind 

 margin of the head. It is just possible that the absence of the 

 gular sutures in many other Ehynchophora is not always, as is 

 assumed to be the case, the result of their coalescence first and 

 disappearance afterwards, but may sometimes be due directly to 

 the strong cbitinization of the integument, which is so general 

 in this group. The disappearance of the prothoracic sutures 

 admits to some extent of a similar explanation, although here it 

 is only in the disappearance of the suture between the sternum 

 and the pleurae that they differ from most of the other Coleo- 

 ptera, and even of this suture there are distinct traces left 

 behind in many of the Ehynchophora. The suture between the 

 notum and the pleurae has altogether vanished, but so it has 

 also in all the Polyphaga, and this character can only be used to 

 distinguish them from the Adephaga, perhaps not even from all 

 of these. 



No one has yet suggested that the Paussidas should rank as 

 the highest of all the Coleoptera ; their adephagous afBnities are 

 too apparent for that. Yet in this family we find the basal 

 sternites of the abdomen fused together, the nervous system con- 

 centrated, and, in some of the genera, the sutures of the pro- 

 thorax almost completely vanished, and the epimera meeting 

 together behind the prosternal process. If we had the external 

 morphology of the body alone to guide us, how should we be 

 enabled to say that the genus Paussus belongs to the lowest and 

 most primitive of all the groups of Coleoptera ? That conclu- 

 sion was arrived at first by a study of its wing- venation, and has 

 since been confirmed by a knowledge of the structure of the 

 sexual organs. External morphology does also, it is true, bear it 

 out, for in the lower genera of the family there is, I find, a quite 

 distinct suture between the pleurae and the notum resembling 

 completely the one met with in all other families of Adephaga. 



That the Ehynchophora are a very highly organized and 

 greatly modified group of the Coleoptera no one now seems 

 to question ; but their position in a phylogenetic scheme of 

 classification depends not so much upon their own high organi- 

 zation as upon the origin of the Phytophaga, the group from 

 which they have presumably been derived. This is a matter 

 which Kolbe has not nearly so fully discussed. He agrees with 



