6 
and has endured probably, under the same laws of modification, 
throughout long geological epochs. 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 so numerously as here. 
Analysis is too easy, and has already been pushed, perhaps, to 
too great an extent. 
The Lamiaires, as far as they are represented in the Amazo- 
nian fauna, seem to present six different types of form : but in 
none are the characters quite constant ; they can only be con- 
sidered as very general, but seldom apply to the whole of the 
species or genera. I have taken into consideration most of the 
parts of structure employed by Messrs. Leconte and Thomson, 
and have brought into prominence others which were neglected 
or only considered subordinate by them, viz. the shape and re- 
lative length of the basal joint of the antennse, the tubercle and 
groove of the middle tibise, and the claw-joint and claws of the 
tarsi. The parts of the mouth, which offer sure characters in 
most other families of Coleoptera, are here of scarcely any 
systematic value. The palpi only occasionally furnish generic 
characters. The ligula, otherwise a very important organ, varies 
greatly in species very closely allied in all other characters. 
Under each subtribe I have quoted such of M. Thomson's groups 
and divisions subordinate to it as are represented in the Amazon 
region. 
Sub tribe 1. Acanthoderit^. Basal joint of the antennse 
shorter than the third, forming an elongate-pyriform club, 
very slender at the base. Middle tibia with the tubercle 
and groove on its outer edge conspicuous. Anterior aceta- 
bula generally angulated externally, the suture more or less 
gaping, but sometimes (Steirastoma) entirely closed. Tarsi 
simple. 
Acanthoderitse, Acrocinitse, Oreoderitse, Dryoctenitae, Poly- 
rhaphitse, and Anisoceritae, Thoms. 
Subtribe 2. AcANTHOCiNiTiE. Basal joint of the antennae much 
elongated, as long as or longer than the third. Middle tibia 
almost always with the tubercle and groove conspicuous. An- 
terior acetabula circular, the suture being closed or nearly so. 
Head narrow. Tarsi simple. 
Acanthocinitae, Trypanidiitae, Colobotheitae, Thoms. 
Subtribe 3. Lamiit^. Basal joint of the antennae moderate 
in size, forming an oblong club thickened from base to tip. 
