2, HETEROMERA. 
the series ; the majority of authors appear to have placed it between the 
series that are, as a rule, pentamerous, and those which are tetramerous 
or pseudo-tetramerous (the Rhynchophora, Longicornia, and Phytophaga), 
not, as Dr. Horn remarks, that they have been supposed to have any 
special relationship to either, nor to be a link between them, but 
apparently from the fact that in the aggregate the amount of tarsal 
joints is one less than in the Pentamera and two more than in the Tetra- 
mera; others again have proposed to place them at the end of the order 
as being a sort of synopsis, in general appearance, of the whole; the best 
plan, however, appears to be to place them immediately before the 
Rhynchophora, which certainly appear to be properly placed last; they 
will then stand as an anomalous group at the end of the ordinary 
Coleoptera, and through the Pythide present a decided affinity towards 
the Curculionide. 
The larve are almost as variable as the perfect insects, and in many 
cases are most curious and extraordinary both in forms and habits ; they 
will be discussed under the various tribes and genera. 
The series is well represented in Europe by about two hundred genera, 
which contain a large number of species, the genera Asida, Pimelia, and 
Mylabris, neither of which are represented in Britain, numbering up- 
wards of two hundred between them; fifty-eight genera are found in 
Britain, but the species are comparatively very few, being only about 
one hundred and twenty in number; the classification is somewhat 
difficult from the fact that the characters that seem trustworthy are so 
liable to exceptions, and in many cases are not very obvious, although 
the insects to be distinguished are in many cases entirely different in 
general appearance; Thomson divides the Heteromera as a whole into 
two divisions, the Globicoxe, which have the anterior coxe globose or 
ovate, and the Conicoxe, in which they are long, conical, and exserted, 
and I have, to a certain extent, followed his arrangement; the genus 
that I have felt most doubt about is Scraptia, which has been very 
differently placed by various authors; it seems, however, to be most 
closely allied to the Mordellide, and I have therefore placed it as a 
separate family near that group, rather than with the Pedilide, which are 
more closely allied to the Anthicide: in point of fact I have not 
adopted the family Pedilide at all, as Xylophilus, including Euglenes, 
appears to be better placed either with the Anthicidee or in a separate 
family, and if we exclude this genus and Scraptia, we have no further 
British representatives of the family. 
J. Anterior coxal cavities closed behind. 
i. Tarsal claws simple. 
1. Anterior coxe globose, rarely oval, not prominent; pen- 
ultimate joint of tarsi very rarely bilobed and spongy 
beneath "0 or tee te ce hott Rene mee arrears 
2. Anterior coxe conical-ovate, prominent, penultimate 
joint of tarsi bilobed and spengy beneath. . . . « LA@Riipz. 
TENEBRIONID2:. 
