568 Mr. K:irby's Description of Insects 



emarginattts. A. 



Long. Corp. unc. 2-^. 



Habitat -. Ex. Mus. D. Francillon. 



Inirod. to But. iii. 446. 



Descr. Corpus nigrum. Caput rugosum. Nasus apice sub- 

 emarginatus. Vertex comu brevi emarginato. Occiput tu- 

 berculis tribus obsoletis. Prothorax antice rugulosus, carina 

 antica transversa utrinque abbreviata. Elytra piceo-nigra 

 leevigata : sutura basi incrassata. 



The group forming the Fabrician genus Geotrapes (Scarobaus 

 Latr.), or Mr. W. S. MacLeay's family of Dyuastidce, has not 

 been closely examined by entomologists, or it would have been 

 discovered to be resolvable into many more genera or sub- 

 genera than Phileurus, Oryctes, and a few others that have been 

 described ; at least if variations in the maxillce, mandihula, and 

 other oral organs are admitted as sufficient indications of generic 

 distinction. Those separated above from Dynastes are not only 

 distinguished by characters derived from these organs, indicating 

 differences in their mode of feeding, but their stature and exter- 

 nal structure also point out some diversity in their habits : the 

 gigantic stature of Mcgasoma, particularly as to width, and the 

 horns of the head and thorax of the male, distinguish the species 

 belonging to it — for instance, M. Acteon, Elephas, Typhon, &c. — 

 from every other group of Dyuastidce. The same remark applies 

 to Dynastes, to which belong D. Hercules, Alcides, Tityus, Nep- 

 tunus, &c. &c. With regard to Archon, at present I am ac- 

 quainted only with the species above described, that seems cer- 

 tainly to belong to the genus. Geotrupes Cadmus F. and affini- 

 ties approach to it, but its maxilla are different. 



Familia 



