216 Mr. J. 0. Westwood on a new Genus 



a slight primd facie resemblance, in general contour, to the more 

 parallel-sided Hadri (such as the //. alpinus and Pawce), — a circum- 

 stance which has suggested its trivial name. 



XVIII. — Description and Figures of a new Genus and Species of 

 Gallerucidse. By J. 0. Westwood, Esq. 



Genus Chalcexus. 



Corpus oblongo-ovale, subconvexum, lseve, nitidum; capite brevi, lato, 

 supra transverso ; facie verticali, magna ; prothorace transverso, capite 

 baud majore; elytris subovalibus. Caput transversum, breve, supra 

 parum convexum ; ocidis rotundatis, angulos anticos laterales occupanti- 

 bus, vertice in medio in tuberculum rotundatum (in cujus parte antica 

 insident antennas basi approximates) paidlo elevatum. Fades magna, 

 quadrata, verticalis, infra truncata ; clypeo parvo, distincto, antice angus- 

 tato ; labro parvo, antice rotundato, margine setoso. Mandibuke lata?, 

 breves, extus rotundatas, antice convexa? ; majciUce parva?, lobo apicali 

 tenui curvato, apice acuto ; palpi majcillares parvi, tenues, articulo lmo 

 brevissimo, 2do et 3t"> longioribus ad apicem sensim incrassatis, 4'° 

 minuto acuminate. Mention parvum, breviter subcordatum, lateribus 

 rotundatis. Labium ejusdem formse et paullo majus. Palpi labiales 

 parvi, articulo basali minuto, 2d° majore sensim incrassato, 3^° parvo 

 acuminate. Antenna; fere corporis longitudine, in medio paullo cras- 

 siores, apicem versus attenuate, articulo l mo capite longiore, tenui, apice 

 clavato, 2do minuto, 3*'° longitudine dimidium articuli lmi excedente, 

 reliquis setosis et sensim longitudine decrescentibus, intermediis cras- 

 sioribus, apicalibus attenuatis, ultimo appendicula minuta conica ter- 

 minato. Prothorax brevis, transversus, capite paidlo angustior, lateribus 

 et margine postico margine tenui elevato instructis. Scutellum trian- 

 gulare. Elytra ovata, convexa, lsevia, tenue marginata. Prosternum 

 simplex. Pedes mediocres, femoribus satis robustis ; tibiis paullo in- 

 curvis ; tarsis dilatatis, subtetrameris ; unyuibus basi appendiculatis. 



Obs. The description and drawing of the parts of the mouth are 

 not so complete as I could have wished, not having considered 

 myself at liberty to dissect the specimens lent to me by the au- 

 thorities of the Leyden Museum. 



Chcdcenus latifrom. (PL XII. fig. 1.) 



C. luteus; antennis in medio, facie, mandibulis, tibiis tarsisque piceisj 

 elytris lsete purpureis ; corpore supra Levi ; elytrorum lateribus serie 

 marginali punctorum impressis. 



Long. corp. lin. 3£. 



Hab. Batang Singalang, In Mus. Lugdunensi. 



Facies in medio parum concava, utrinque lineis duabus impressis 



