South American species of Diahrotica. 17 



The difference in the relative length of the second and 

 third joints of the antennae, mentioned by Mr. Jacoby in 

 the 'Biologia,' is sexual; in the $ the two joints are 

 of nearly equal length, in the ? the third is distinctly 

 longer. 



Spec. 21. Diahrotica adornata. 



Anguste ovata, postice ampliata, convexa, flava, nitida, pectore, 

 tibiis, tarsis capiteque nigris, antennis ad basin piceis, articulis nono 

 decimoque albidis ; thorace convexo, tenuiter remote punctato, 

 utrinque obsolete foveolato ; elytris subcrebre punctatis, ad latera 

 plicatis ; nigris, utroque limbo externo, apice dilatato, macula 

 oblonga aut snbrotundata infra basin, fasciaque vix pone medium, 

 fulvis. 



Mas. Antennis modice robustis corpori aequilongis, articulis 

 secundo et tertio brevissimis ; abdominis segmento anali late 

 truncato. 



FoEM. Antennis corpore brevioribus, minus robustis, articulo 

 tertio secundo longiori. 



Long. 2i— 3 lin. 



Hah. Cayenne. My collection. 



Head not longer than broad ; clypeus with a slightly elevated, 

 longitudinal ridge ; antennae robust, equal to the body in length 

 in the ^ , rather shorter in the J , filiform, the second and third 

 joints short, equal and submoniliform in the ^; in the $ the 

 second joint is short, subovate, whilst the third is one-half longer, 

 the fourth in both sexes is longer than the preceding two united ; the 

 four lower joints pale piceous, the ninth and tenth yellowish white. 

 Thorax about one-fourth broader than long ; sides nearly parallel 

 and slightly sinuate from the base to beyond the middle, thence 

 obliquely converging towards the apex ; the hinder and anterior 

 angles subacute ; above convex, obsoletely foveolate on either side, 

 shining, impuuctate. Elytra oblong, slightly dilated posteriorly, 

 convex, very minutely punctured. 



Spec. 22. Diahrotica viridimaculata, Jacoby. 



Proc. Zool. Soc, 1878, p. 150. 



Anguste orata, postice ampliata, convexa, prasina, nitida, pec- 

 tore, tibiis, tarsis, scutello capiteque nigris, antennis ad basin piceis, 

 ad apicem albidis ; thorace leviter trifoveolato, fovea tertia minus 

 distincta, interdum obsoleta ; elytris distincte punctatis, infra callum 

 humeralem leviter plicatis ; nigris, utroque limbo externo, apice 

 dilatato, maculis duabus, una rotundata subbasali, altera apicali ad 



TRANS. ENT. SOC. LOND. 1890. — PART I. (APRIL.) C 



