401 



INTRODUCTION TO THE 



pelled to admit that Entomology has made far more raj^id 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 "-reatly to our knovi^ledge of these tribes of animals ; but it has been especially 

 vi'ith 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 confine myself more espe- 

 cially to those natural groups which Latreille, in his other works, regarded as " natural 

 families," — groups equivalent in general with the Linnsean 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 

 earUer 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 obsen'ed that Latreille 

 himself, in his Coiirs (TEntomologie, 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. Hexapoda. — 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- 

 sita, 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 iishes. The Arachnida are terrestrial, and 



thus indicate the Mammalia. That the Myriapoda 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 ciass^ 

 that of birds.] 



