ON" DECOMPOSED VEGETABLE MATTER. 65 



s&piuspubescens, coleoptris abdomen postice non ob- 

 tegentibus. Thorax sape comutus, vel mucronatus 

 vel excavalus. Scutellum distinctum, triangulare. 

 Sternum nunquam production. Pedes validi, tar- 

 sorum unguibus indivisis. 



Observations. 



This family is remarkable as' well for containing some 

 of the most bulky of coleopterous insects, as for the dif- 

 ference which often occurs in the external appearance of 

 the sexes. It may be separated from the Trogida and 

 Geotrupidcc with ease on examining the labrum, which 

 in the Dynastida is almost always concealed under the 

 clypeus, instead of being distinct as in the other two cases. 

 I have here, as also in the corresponding family of the 

 circle of Thalerophagous Petahcera, in some manner 

 disregarded the shape of the maxilla? for the sake of 

 general habit. Latreille in his various works has made a 

 distinct division of the Dynastida, which have their max- 

 illse unarmed. But the general habits and appearance of 

 the genera Oryctes and Dynastes being so very similar, 

 and several insects occurring to fill up the chasm between 

 them, I conceived that it would be an artificial interrup- 

 tion of the order of Nature, to place two such insects as 

 Oryctes nasicornis, Illig. and Scarabeus .Boas, Lat. in 

 different families. 



The DynastidcB live either in rich vegetable mould or in 

 the putrid detritus which results from the decomposition 

 of trees. Perhaps also some are strictly lignivorous, par- 

 ticularly the large foreign species of Dynastes ; but the 

 truth is, that the economy of these insects has hitherto been 

 so little studied, that it is almost entirely from analogy that 



F 



