154 Mr. S. S. Saunders's Descriptions of some 



Fam. CisTELiD^. 

 Genus Prostenus, Latr. (Fam. Nat.), Perty, Ins. Bz. 

 Prostenus laticornis. Plate XIV, fig. 4. 

 Elongatus gracilis, viridi-cupreus, nitidus, antennis elongatis 

 nigro-violaceis, apicem versus fortiter dilatatis, elytris punctato- 

 striatis, pedibus piceo-ferrugineis, femoribus incrassatis. 

 Long, corporis 6 lin., lat. I4 lin. 

 Habitat in Brasilia, prope Monte Video. 

 In Mus. nostro. 



Descr. Antennce corporis longitudine nigro-violaceae, articulis 

 quinque basalibus plvis minusve piceo peUucidis, ad apicem 

 purpureis ; caeteris fortiter dilatatis, et (prseter ultimum) sub- 

 trigonis, disco parvim concavis, obsolete rugosis, lineaque \ix 

 distincta in longitudine divisis ; articulo extremo frondiformi. 

 MandibulcE picese, ad apicem nigrae. Caput atque thorax viridi- 

 cuprea, confertissime punctata, nitida, pilis longulis erecti« 

 parce induta; hie convexus, subquadratus, lateribus rotundatis 

 Elytra elongata concoloria, nitida, ad basin elevata, humeris 

 prominentibus, regione intermedia subdepressa, disco pilis non- 

 nullis suberectis regulariter dispositis, ad apicem crebrioribus ; 

 singula striis punctatis novem (quarum suturalis valde abbrevi- 

 ata, et in proximo, prope basin demersa), punctisque nonnullis 

 majoribus unde exeunt pili ad interstitia impressa, serieque ad 

 marginem lateralem, antice duplicem ordinem sequente, lateri- 

 bus prope basin subten'olutis. Corpus infra piceum, viridi- 

 cupreo sufFusum. Pedes saturate piceo-ferruginei ; femoribus 

 incrassatis, ad basin tenuissimis ; tibiis hirsutis vix recurvatis ; 

 unguibus magnis. 

 This insect would probably enter into the extensive genus Pro- 

 stenus of Dejean's Catalogue, which is there placed as synonymous 

 with Lystronychiis ; but the elongate form, shining surface of the 

 bodj^ greatly dilated antennae, and incrassated femora are important 

 characters in which it varies from the tjrpe of the latter genus 

 {Helops equestris, Fabr.), so that I have felt disposed to follow Dr. 

 Perty, who considers the two genera as distinct. As however 

 neither characters nor type of Prostenus have been laid down by 

 Latreille in the Fam. Nat., in which work alone the genus is to be 

 found recorded by that author, it is impossible to say whether the 

 name Prostenus may not have been subsequently expunged by him 

 intentionally, and the name Lystronychus introduced synonymously 

 in its place. In such case it would be well that the Prostenus of 

 Perty should receive a distinct denomination in order that confusion 



