COLEOPTERA. 17 



Phileurus, Lat. — Geotrupes, Fab. 



The Phileuri only differ from the Scarabaei in their mandibles, 

 which are straighter, destitute of sinus or teeth on the outer side, and, 

 in their depressed body, the thorax of which is dilated and rounded 

 on the sides *. 



Our second division contains Scarabaeides, closely allied to the pre- 

 ceding in some respects, but also closely approximating to various 

 Melolonthae, and particularly to the Cetonise, which they resemble 

 externally, but from which they differ in the arrangement of the 

 mouth ; Fabricius and Olivier even arranged most of these Insects 

 with them. Their body is generally shorter, more rounded, smoother 

 than that of the Scarabasi, and decorated with brilliant colours. The 

 head and thorax are identical, and without any particular projection 

 in both sexes. The anterior margin of the labrum is almost always 

 exposed or apparent. The maxilhie are entirely scaly, as if trun- 

 cated at the extremity, and furnished on the inner side with five or 

 six strong teeth. The mcntum is proportionally shorter and wider 

 than that of the same Coleoptera, and less narrowed superiorly. The 

 mesosternum is frequently prolonged into a horn or blunt point, ex- 

 tending between the second legs and even beyond them. The scu- 

 tellum is usually large. The tarsial hooks are generally unequal. 

 With the exception of a small number, these Xylophili are peculiar to 

 the equatorial covmtries of the western continent. 



Here, as in all the preceding Scarabaeides, we find no axillary 

 piece f filling the interval comprised between the posterior angles of 

 the thorax and the exterior angles of the base of the elytra. 



We will first speak of those subgenera in which the middle of the 

 pectus presents no point or horn. 



Hexodon, Oliv. Fab. 



The body is almost orbicular and plane beneath ; the head square, 

 and received into a deep emargination of the thorax; the outer mar- 

 gin of the elytra dilated and preceded by a small groove; the legs are 

 slender, and the hooks of the tarsi very small and equal. 



The labrum is apparent, The antennal club is small. The max- 

 illee are strongly dentated :j:. 



Cyclocephala, Lat. — Chalepus, Mac L. — Melolontha, Fab. 

 The body ovoid ; head free ; elytra slightly bordered, without any 



* G. dydimus, vulgus, depressus, Fab. Certain undescribed species from Brazil and 

 Cayenne, somewhat analogous to Sinodendron, have a thicker body, and connect the 

 Phileuri with our Scarabaeides, or the Geotrupes of Fabricius, a genus which has 

 not been sufficiently stiidied with respect to the organization of the parts of the 

 mouth. 



•f- A lateral portion of the sternum larger and thicker than usual, and which, per- 

 haps, corresponds to that small rounded scale (the tegula of some authors) found at 

 the origin of the superior wings of Hymenoptera. See the Mem. sur le thorax des 

 Insectes, by M. Audouin. 



I See Oliv., and Lat., Gener. Crust,, II, p. 106. 



