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 fovese ; 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 antennae and the palpi are red ; the remaining joints of the 

 antennae are brownish ; the labrum is pitchy, sometimes reddish. 



This appears to be the most common species of Chlcenius in the 

 neighbourhood of Maldonado, La Plata ; it is possibly the Ch. Brazi- 

 liensis of Dejean's Supplement, 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. 3. Chlcenius Westwoodii. 



C. obscure niger, supra obscure viridis ; antennis pedibusque tes- 

 taceis ; antennis ad apicem tarsisque fuscescentibus ; capite 

 subnitido ; thorace angustato, postice paulo attenuato, foveis 

 duabus, punctulisque minutissimis, impresso ; elytris striatis, 

 interstitiis planis crebre et minutissime punctulatis. 



C. Platensi fere similis et paulo minor et thorace angustiore. 



Long. 5^- lin. ; lat. 2^ lin. 



I have applied the name Westwoodii to two specimens of Chlcenius 

 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 rugae, 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 fovese 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 striae of the elytra are rather 



