354 Mr. Waterhouse on Carabideous Insects. 
ralis of North America; the head is larger, and the thorax more at- 
tenuated behind. 
The head and thorax are either green or brassy—sometimes in- 
clining to copper colour; the head is glossy, and the thorax but lit- 
tle so, it being rather thickly and coarsely punctured, excepting on 
the disc, where the punctures are less numerous ; whilst the head is 
impunctate, but has on the hinder part some very minute transverse 
wrinkles ; the eyes are rather prominent. The thorax is about one- 
third broader than the head, has a distinct dorsal channel, and large 
and somewhat shallow posterior fovez ; it is distinctly attenuated 
behind, and broadest near the fore part. The elytra are destitute of 
gloss, of an obscure dusky green colour, and rather delicately punc- 
tate-striated ; the interstices are flat and densely covered with very 
minute punctures, and with a moderately strong lens a slight pubes- 
cence is observable. The body beneath is black and slightly pubes- 
cent, and the apical portion of the abdomen is obscurely margined 
with testaceous : the legs are pale testaceous; the three basal joints 
of the antennz and the palpi are red; the remaining joints of the 
antenne are brownish ; the labrum is pitchy, sometimes reddish. 
This appears to be the most common species of Chlenius in the 
neighbourhood of Maldonado, La Plata; it is possibly the Ch. Brazi- 
liensis of Dejean’s Supplément, but that insect is described as six 
French lines in length, and it is not improbable, therefore, that it is 
a nearly allied but larger species. Five specimens are in the collec- 
tion of Mr. Darwin. 
Sp. 38. Chlenius Westwoodii. 
C. obscuré niger, supra obscuré viridis ; antennis pedibusque tes- 
taceis; antennis ad apicem tarsisque fuscescentibus; capite 
subnitido; thorace angustato, posticé pauld attenuato, foveis 
duabus, punctulisque minutissimis, impresso; elytris striatis, 
interstitiis planis crebré et minutissimé punctulatis. 
C. Platensi feré similis et paulo minor et thorace angustiore. 
Long. 54 lin.; lat. 24 lin. 
I have applied the name Westwoodii to two specimens of Chienius 
brought from Maldonado by Mr. Darwin, which in size nearly agree 
with the common English species (Ch. vestitus); as regards the 
form they approach more nearly to the Ch. Platensis just described, 
having the head and thorax longer in proportion to the elytra, but 
the thorax is considerably narrower than in either of these insects, 
being scarcely broader than the head. 
The head green, somewhat glossy, and covered above with most 
minute ruge, which are scarcely discernible unless through a strong 
lens ; the eyes are prominent ; the labrum and base of the mandibles 
are pitchy-red. The thorax is but little broader than the head, 
longer than broad, and slightly attenuated behind; the dorsal chan- 
nel is but faintly marked, and the posterior foveze are shallow and 
rather long; the upper surface of the thorax as well as that of the 
elytra is green and destitute of gloss; the punctures on the-thorax 
are very minute and scattered; the striz of the elytra are rather 
