216 LONGICORNIA. [ Longicornia. 
first and second joints of the posterior tarsi), claws almost always simple, 
but rarely cleft or appendiculate. The colouring of the species is very 
variable, and in some of the exotic species is very handsome ; it appears, 
however, to be rarely metallic. 
The Longicornia are closely connected with the Chrysomelide, and 
although no one is likely to confuse the members of the two groups, 
yet the difference between them is hardly capable of being expressed 
satisfactorily in words. Dr. Horn (Classification of the Coleoptera of 
North America, p. 269) says that ‘“‘so far the essential difference 
between the Tetramera, of which the larve feed upon wood, and those 
feeding upon cellular vegetable tissues, has eluded observation. We 
can merely at present observe that a slight approximation to it seems to 
be made in the fact, that in the Cerambycide there is a tendency in 
the epimera of the metathorax to extend to the sides of the ventral 
segments, while in the Chrysomelide the first ventral segment is pro- 
longed forwards at the sides to meet the metathorax, thus showing 
probably a lower, though necessarily more recent type, which could 
have existed only since the development of the higher broad-leayed 
plants.” 
The members of this group, owing to their habits of life in the larval 
state, are probably among the most archaic of the Coleoptera ; they can 
live a long time within the trunks of trees in which they take up their 
abode, even if they are immersed in water, and are, of course, to a great 
extent protected against external enemies; the chief collector and 
describer of the group, Mr. H. W. Bates, in commenting upon the vast 
amount of different forms belonging to the family, remarks as follows :*— 
“Tt is one of those groups of insects in which nature, in striving after 
strong individuality in the species, seems to have changed or adapted 
those parts of structure upon which we rely for characters of genera 
and groups of genera. The family, too, is found throughout all parts 
of the world where woody vegetation exists, and has endured, probably, 
under the same laws of modification, throughout long geological periods. 
The diversity of specific forms seems endless, running into infinite 
varieties of grotesque, ornamented, and extraordinary shapes; and 
nearly every species has structural peculiarities for its specific characters ; 
so that in no family can genera be made so easily and numerously as 
here. Analysis is too easy, and has already been pushed, perhaps, to 
too great an extent.” 
The larve of the Longicornia are large fleshy insects, which, as a rule, but 
not always, have the prothorax much enlarged in comparison with the suc- 
ceeding segments, and are more or less gradually narrowed behind; the meso- 
aud metathorax are often very short; the abdominal segments are nine in number, 
and the anal segment is rounded and continuous with the body, presenting the 
appearance of a tenth segment; the head is corneous and depressed, armed with 
* Contributions to an Insect Fauna of the Amazon Valley. Coleoptera, Longi- 
cornes. Part I., Lamiaires, pp. 5-6. (Annals and Magazine of Natural History, 1861 ) 
