362 Mr. H. W. Bates on the 
account. In the great majority of genera of Carabici, as is well 
known, the males are distinguished from the females by the 
dilatation of the anterior and sometimes of the middle tarsi; the 
number of joints dilated and the nature of the clothing of the 
palms affording characters whereby to distinguish genera and sub- 
families. But the other parts of the body offer only very slight 
differences in the sexes. In the 4gre@ the differences are numerous 
and varied. In some species the anterior tarsi show a dilatation 
of the first joint in the male; and in others it is the hind feet 
that exhibit this partial enlargement: the femora in the males of 
nearly all are strongly thickened; and in one series of species 
the middle and hind tibize are peculiarly bent and flattened, and 
hirsute on their inner side in the same sex. This latter character 
is accompanied in the same species by dense patches of hairs 
arising from closely-punctured spaces in the middle of the meta- 
sternum and abdominal segments. Some species again possess 
this hairy clothing, without the existence of any peculiarity in the 
shape of the tibiae: this clothing in others often extends to the 
bases of the femora and the hind trochanters. In all the species 
whose males are thus clothed the under surface of the body of 
the females is naked and the tibia simple; but in a numerous 
group this sex offers a singular peculiarity in the antenne ; the 
eighth to tenth joints being out of proportion shorter than the 
rest, and the eighth generally extremely abbreviated. The males 
also have generally more broadly dilated palpi, as is the case in 
the Carabi and other genera having these organs hatchet-shaped. 
There is this to be noted, however, in the genus, that, whilst some 
species show these sexual differences in a high degree of perfec- 
tion, there are others in which they are reduced almost to nd. 
The Baron Chaudoir, in his chief work on the Agre, published 
in the Annals of the Entomological Society of France, 1861, has 
divided the genus into two, viz. Agridia and Agra. Agridia is a 
tolerably natural group, and may be adopted or not according as 
the student has analytical or synthetical tendencies, but the sharp- 
ness of its definition from Agra is much affected by the inter- 
mediate character of the first group of the latter genus (the 
Agre spurie of Chaudoir). I have followed M. de Chaudoir in 
the subordinate grouping of the genus, which seems to me most 
natural. 
Lastly, I may say, by way of hint to future collectors in 
Tropical America, that the best season for Agre is the showery 
weather at the commencement of the rainy season, especially if 
the preceding dry period has been of long duration. When the 
