17'-^ CLASS INSECTA. 



less solid below. The number of articulations in the tarsi 

 varies from three to five. To judge by analogy, the coleop- 

 tera called monomera, have probably three articulations in 

 the tarsi ; but the first two are invisible. This section and 

 that of the dimera, have been suppressed. 



The coleoptera undergo a complete metamorphosis. The 

 larva resembles a worm, having a scaly head, a mouth 

 analogous, in the number and functions of its parts, to 

 that of the perfect insect, and usually six feet. Some 

 species, few in number, are without feet, or have but simple 

 mammellae. 



The mesothorax is always short and narrow, and the 

 metathorax, often spacious, is furrowed longitudinally in 

 the middle. 



The nymph is inactive, and takes no nutriment. The ha- 

 bitat, the mode of life, and the other habits of these insects, 

 either in their first or last stage of existence, vary very con- 

 siderably, 



I divide this order into four sections, according to the 

 number of articulations in the tarsi. 



The first comprehends the penfamera, or those of which 

 all the tarsi have five articulations ; and it is composed of 

 six families, of which the first two are distinguished from the 

 others by the existence of a double excrementitious appa- 

 ratus. According to M. Dufour, the silpha, a genus of 

 the fourth family, also exhibits one, but single, or one side 

 alone. 



The first family of the Pentamerous Coleoptera is 



The Carnivora, Cuv. (Adephages, Clair.), 



with two palpi on each jaw, or six in all. The antennae are 

 almost always thread or silk- formed, and simple. 



The jaws are terminated by a scaly piece, talon-formed, or 



