Sa NATURAL AFFINITIES 



of affinity carried even still further, as in the genera Dasy- 

 gnathus and Amblj/terus, of which descriptions will be 

 found in the Appendix. But it is in the construction of the 

 mouth that the most remarkable analogy betrays itself, 

 and consequently is in some degree evident in the manner 

 of Uving, so that each saprophagous insect may be said to 

 have a thalerophagous one corresponding to it. 



Such analogies, nevertheless, must be gathered from the 

 most general view that can be taken of the different groups, 

 and even then are often obscured by real or apparent ex- 

 ceptions. So that, however interesting to the philosopher, 

 they serve but to show that in the creation a general plan 

 was pursued, the infinite shades of deviation from which, 

 in the execution of the details, must render its complete 

 developement by our limited faculties almost hopeless. 

 But to return : — It will next be perceived that each of the 

 columns into which the Petalocera are divided, forms a 

 circle ; for on the one side we find the Geotrupidce, con- 

 nected Avith the Dynastida by means of the genera Or- 

 -phnus, MacL., and Oryctes, Lat.; and on the other, the 

 Kutelidcz with the Atioplognathidoi by means oiPelidnota 

 and Areoda, both new genera, now for the first time pub- 

 lished. — Again : tliese two circles will be found in a manner 

 to touch one another at the families of Dynastidcc and 

 AnoplognathidfE, which are, as before stated, intimately 

 connected with each other by such genera as Dasygnathus 

 and Amblyterus- 



The following figure, therefore, which represents two 

 circles, touching one another and composed each of five 

 analogous ganglions, will express well the natural position 

 of the Petalocera among themselves. 



