in the Tetramerous and Trimerous Coleoptera. 65 
five sections: the first consisting of Pentamera, or insects having 
five articulations to each of the tarsi of their six feet ; the second, 
of Heteromera, or insects having five articulations to the tarsi of 
the four anterior feet, and only four to those of the two last ; 
the third consisting of Tetramera, or insects having four articula- 
tions to each of the tarsi of the six feet; the fourth, of Trimera, or 
insects having each of the tarsi with only three articulations ; and 
the fifth, of Dimera, or insects possessing only two articulations 
to each of the tarsi of the six feet. In the Règne Animal we have 
a sixth section added to these, called Monomera, the insects of 
which are said to have only one joint to the tarsus. 
It is unfortunate for this system, thatif it be considered as 
an artificial one, in which all coleopterous insects are to find a 
place, very little examination is sufficient to prove that multitudes 
of Coleoptera exist which are neither pentamerous nor monome- 
rous, nor, in short, belonging to either of the above sections ; such 
as, for instance, the typical species of Onitis, the males of which 
appear to have no anterior tarsus* ; the genus Cryptophagus}, 
where the males and females differ in the number of joints to 
their tarsi; the aquatic genus Hydroporus f, which is said to have 
four joints to the tarsi of the four anterior feet, and five to the 
two last, &c. &c.: all of which ought to form, by parity of 
reasoning, so many new sections. _It is equally unfortunate that, 
if this system be considered as a natural one, M. Latreille and 
others of the more scientific entomologists who have adopted it, 
appear to have set it at nought whenever it interfered too glaringly 
luny and in Samouelle's Compendium has most properly placed the Pselaphide next 
to the Staphylinida. . In the Hore Entomologicæ, page 6, I attacked the system gene- 
rally, showing it to be “by no means natural.” 
* Onitis Sphinx and its affinities, for instance. In Onitis Apelles and its affinities 
we may, however, observe the tarsus; but then these are species that go off to Oniti- 
cellus. See Hore Entom. p. 56. 
+ Hore Entomologice, p. 7. t Ibid. p. 7, note. 
VOL. XV. K 
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