4i 8 Memoirs on the Coleoptera 



outline, reminding us somewhat of Diastethus and other similar 

 genera in the Centrinini. The very brilliant metallic coloration, 

 however, distinguishes the species from any others of the subfamily 

 and constitutes one of the more important of the generic characters. 

 The beak is thick, compressed, only very moderately arcuate, not 

 separated from the head by an obvious impression, sparsely punctate 

 and with stout decussate mandibles, the left sometimes shorter than 

 the right and more truncate. The antennae are inserted far beyond 

 the middle in both sexes and are short and more or less thick, at 

 least distally, the club very moderate and conically pointed; the 

 funicular joints are often, or perhaps generally, flattened, and 

 deeply impressed at the side. The prosternum is not modified, 

 except by feeble impression, and separates the coxae by their own 

 width (chevrolati) to much less (cyaneus) ; the legs long, thick and 

 shining, with uninflated and mutic femora, which are generally 

 feebly swollen at apex, the tibiae smooth, with short thick inner 

 uncus at apex, the tarsi with transverse second and dilated third 

 joints and moderate, closely connate claws. The prothorax is 

 tubulate at apex, the basal lobe broadly rounded, the scutellum 

 transversely triangular and the elytra feebly striato-punctate. The 

 species are numerous throughout the neotropics, but no attempt 

 has been made to classify them in any thorough manner. They 

 are divisible quite readily however into several groups, based in the 

 main upon the diverse manifestation of sexual characters as follows: 



Humeral swelling more or less conspicuously prominent; male with one or two 

 foveiform impressions on the fifth ventral segment 2 



Humeral swelling very feeble; male without impression on the fifth ventral, its 

 apex with a short truncate median lobe, which is altogether wanting in the 

 female 14 



2 — Elytra with an irregular impression involving the bases of the second and 

 third striae; fifth ventral segment not foveate in the female excepting feebly 

 in minuens 3 



Elytra without the indicated impression, the bases of the second and third striae 

 each forming, however, a very clearly defined but short sulcus; abdomen as 

 in the preceding section 11 



Elytra perfectly even basally, all the striae attaining the base without dilatation; 

 fifth ventral (c? ) with a single deep apical fovea, or ( 9 ) without impression; 

 body brilliantly cupreous 12 



Elytra as in the preceding; fifth ventral of both male and female having two 

 deep approximate apical foveae, a little larger and subconfluent (<?), or 

 smaller and always separated ( 9 ) 13 



3 — Color uniform dark blue, sometimes suffused with violaceous; body of larger 

 size 4 



Color uniformly bright green, the humeri sometimes feebly and suffusedly cu- 

 preous 7 



Color bright green or bluish, the anterior parts of the pronotum and a humeral 

 and subapical area on each elytron — longitudinally united at the outer margin 

 — cupreous ; 10 



4 — Humeral prominence broadly and obtusely rounded at apex 5 



