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INTRODUCTION TO THE 
pelled to admit that Entomology has made far more rapid strides in these days than 
heretofore. The establishment of Entomological Societies in France and England has 
called forth the exertions of many students, who, in every branch of the science, have 
added greatly to our knowledge of these tribes of animals ; but it has been especially 
with reference to the description of new genera and species that the greatest strides 
have been made. To attempt, within the very limited space devoted in this edition 
to the Invertebrated Animals, to give even a list of all the new genera established since 
1829, would be useless; and this portion of the work must therefore necessarily be 
treated in a plan somewhat at variance with that of the vertebrated portion. As we 
cannot, therefore, give the genera, subgenera, sections, subsections, and other inferior 
groups, which, in the majority of instances, rest upon isolated structural characters, 
often of trivial nature (such as the number of joints in the antennae, the number of 
cells or spaces formed by the veins of the wings, &c.), I shall coniine myself more espe- 
cially to those natural groups which Latreille, in his other works, regarded as ‘‘ natural 
families,” — groups equivalent in general with the Linnaean genera, to which but few 
additions of importance have been made, and of which the knowledge will afford a good 
and sufficiently general view of Entomology, — noticing, however, their sectional distri- 
bution, and the more remarkable of the groups now termed genera. 
It is in the first place, however, necessary to observe, that the limits of the sub-kingdom 
Articulata, and its primary divisions, have recently formed the subjects of much discus- 
sion. The researches of Drs. Nordmann, V. Thompson, and Burmeister have clearly 
proved, not only that the Cirrhipedes, placed by Cuvier amongst the Mollusca, are, in their 
earher stages, active Entomostraca; but also that the Lernsese, placed by Cuvier amongst 
the intestinal worms, are similarly active, and furnished with articulated legs in their 
early state. The relation of the Annelides with some of the wingless insects has also 
been strenuously maintained by some writers, who have deemed the internal organisms 
of higher importance than the circumstance of the limbs being articulated. 
With respect to the primary divisions, or classes, into which the jointed-legged 
Articulata (or the Condylopa of Latreille) are formed, it is to be observed that Latreille 
himself, in his Cours d' Entomologie, published subsequently to the second edition of this 
work, has modified his views herein set forth, in the following manner : — 
Condylopa — {Insecta, Linn.) 
1. Apiropoda. — With more than six feet ; destitute of wings. 
Class 1. Crustacea. 
2. Arachnides. 
3. Myriapoda. 
2. Hexapod A. — Including the single 
Class 4. Insecta.* 
Here we find the Myriapoda, which Latreille had in this work united with the true 
insects, raised to the rank of a class, whilst the orders Thysanura and Anoplura {Para-- 
sit a, Latr.) still remained with the fourth class. 
Mr. M‘Leay, however, has united these two orders with the Myriapoda, forming 
* [Without attaching so much weight to considerations resting 
solely upon analogical resemblances, too often of a very fanciful 
nature, as some of our recent English naturalists (M'Leay, Swainson), 
we may notice that these four groups seem to represent the four pri- 
mary groups of vertebrated animals. The Crustacea are aquatic, and, 
as such, are analogous to fishes. The Arachnida are terrestrial, and 
thus indicate the Mammalia. That the M3Tiapoda are analogous to 
the reptiles is sufficiently evident by comparing a Scolopendra with ' 
the skeleton of a Snake, or an lulus with a perfect one (whence 
Latreille named the latter Anguiformes) ; whilst the true insects, fur-| 
nished with wings, at once represent the only other winged class—! 
that of birds.] 
