190 M. JACOBS 



sides straight, the anterior angles oblique, the basal margin ac- 

 companied by an impressed, finely punctured groove, the sur- 

 face minutely granulate and extremely finely punctured, the 

 punctures only visible under a strong lens; elytra broad, mo- 

 derately convex, finely punctate-striate, the interstices flat and 

 impunctate, below black and shining, the legs fulvous or fiavous, 

 the femora more or less piceous. 



But few species of Chaetocnema have been described from the 

 Brazils, the present one which is of very small size, belongs to 

 the group having an impunctate head ami may be distinguished 

 from C. braziliensis, Baly in the much less strongly punctured 

 elytra and their flat not convex interstices. 



17. Diabrotica univittata, sp. n. — Pale testaceous, the antennae 

 black, thorax subquadrate, impunctate, the sides with a narrow 

 piceous stripe, elytral extremely sparingly and finely punctured, 

 with a broad discoidal piceous band, extending to the apex. 



Length 4 mill. 



Head impunctate, fiavous, the frontal elevations small, but 

 distinct, lower portion of face pale testaceous, penultimate joint 

 of the palpi thickened, antennae black, the basal joint more or 

 less fiavous below, second and third joints very short, equal, 

 fourth joint very elongate , rather longer than the following- 

 joints ; thorax scarcely broader than long, the sides straight, 

 feebly rounded at the middle, the disc obsoletely bifoveolate, 

 tiavous, impunctate, the sides with a narrow piceous stripe, not 

 quite extending to the lateral margins, elytra wider at the base 

 than the thorax, scarcely perceptibly punctured, each elytron 

 with a broad longitudinal fuscous band, not extending to the 

 apex, the latter also with a small piceous spot; below and the legs 

 fiavous , the four posterior tibiae and tarsi , more or less piceous. 



This small Diabrotica almost entirely resembles D. nymphaea, 

 Jac. (Biolog. Centr. Amer.) in its system of coloration but belongs 

 tu that section of the group, having the second and third joints 

 of the antennae very short ; in D. nymphaea the third joint is 

 very elongate. 



