* 
in the Tetramerous and Trimerous Coleoptera. 13 
even when we consider it in no other light than as affording 
means of description. As a medium for expressing natural affi- 
nities, it had already been sufficiently characterized by the 
learned entomologist who has been the principal source.of its 
celebrity, when he said, “ Articulorum tarsorum progressio nu- 
merica decrescens in methodo naturali non admittenda." This as- 
sertion I have repeatedly proved to be true, notwithstanding 
its having been tacitly retracted by M. Latreille, when he 
brought forward this system in the Règne Animal distribué 
aprés son Organization. To overturn, therefore, this arrangement 
of Coleoptera altogether, and to demonstrate that it does not 
even possess the merit of being an accurate artificial one, it only 
remained to show that this numerical progression of tarsal joints 
does not really exist in nature, and that we have been hitherto 
giving those very groups of Coleoptera, which perhaps are most 
familiar to our eyes, names that in point of fact are quite 
erroneous, | 
VOL. XV. £ III. No- 
