DYNASTIISLE 107 



the body and simply bidentate anterior tibiae might possibly imply 

 generic difference, which would be revealed more decisively in 

 the male. 



Subfamily DYNASTIN^. 



This great subfamily, comprising a remarkable variety of form 

 and habitus, includes among its host of species the largest of the 

 known Scarabaeidae. There are many structural features common 

 to the Dynastinae and Rutelinae, for example the corneous ligula is 

 soldered rigidly to the men turn and the almost uniformly lo-jointed 

 antennae always have a 3-jointed club in both subfamilies. The 

 Dynastinae differ radically, however, in having the tarsal claws 

 equal in size, excepting the anterior in the males of certain species; 

 but there are some genera the assignment of which to the Rutelinae, 

 Dynastinae or Cetoniinae it is difficult if not impossible to decide 

 under our present knowledge. The mandibles are nearly always 

 exposed, though concealed in most of the Cheiroplatids, and are 

 generally in part ciliate, and the anterior coxae are transverse and 

 deeply seated. It is unsafe to add further to these few diagnostic 

 characters, in view of the diversities of structure and the numerous 

 exceptions, further than to say that corneous thoracic and cephalic 

 processes in the males are as characteristic of the Dynastinae, as 

 their absence is of the Rutelinae. It should be added also, that the 

 labrum is always visible in the Rutelinae and almost invariably 

 hidden under the clypeus in the Dynastinae. Excepting in the 

 isolated Cyclocephalini, the clypeus is but rarely truncate as is 

 so frequently the case in the preceding subfamily, but is generally 

 more or less acuminate and reflexed at tip and variously dentate to 

 edentate. The scutellum varies greatly in the Rutelinae, being 

 sometimes small and occasionally enormously developed, but here 

 there is a remarkable uniformity, it being generally very moderate 

 in size. Finally it is to be noted that metallic lustre of the integu- 

 ments is a very common character among the Rutelids but is very 

 rare among the Dynastinae. 



As far as the North and South American fauna is concerned the 

 tribes may be arranged as follows, the mandibles being corneous 

 throughout: 



Labial palpi inserted at the sides of the ligular part of the mentum. ... 2 

 Labial palpi inserted on the inner face of the ligular plate 7 



