ON FIVE FAMILIES OF PETALOCERA. 51 



rules and definitions, is an attempt as absurd as it would 

 be to investigate truth by means of a set of prejudices. 

 He felt that the student in the more profound branches 

 of the science ought to have already paved the way 

 for this sort of research, by that intimate and extensive 

 knowledge of species which can always be most easily 

 acquired by artificial methods. We see, therefore, that 

 naturalists must always owe a large portion of gratitude 

 to those who may by the help of artificial systems have 

 made the productions of nature generally known : for it is 

 with the materials collected by the humble labours of these 

 indefatigable men, that the world can alone expect that 

 the foundations of our knowledge with respect to nature 

 should ever be laid. 



Fam. I. GEOTRUPID^E. 



Antennae decern vel undecim articulate ; 



Articulo basilari subconico, vix elongato ; 

 Capitulo magno, triphyllo, subgloboso. 



Labrum exsertum, crustaceum, transversum, subquadra- 

 tum ; margine antico ciliato. 



Mandibulae exserta, cornea, validissima ', sWbtrigona, de- 

 presses, ad apicem subarcuata. 



Maxillae Crustacea; margine interno vel apicali membra- 

 naceo autfimbriato hirsuto. 



Palpi maxillares Jiliformes. 



Labium bipartitum, mento bifido vel integro. 



Caput lateribus utrinque ante oculos auriculatim sapius 



dilatatis; Clypeo^arw, angulato, depresso. Corpus 



orbiculato-ovale aut suborbiculare, undique convex- 



um. Thorax latius quam longius extensus ; Scutello 



E2 



