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XXXII. Characters and Description of a new Genus of the Family Melolonthide. By 
Joun Curtis, Esq., F.L.S., &c. Communicated by the Secretary. 
Read February 10, 1835. 
Ina collection of insects sent to me by Mr. A. Mathews, and formed by him in Lima 
and its neighbourhood, the following species appeared to me so peculiar in its struc- 
ture that I thought it particularly worthy of being described and figured. 
Ordo Corzoprera. 
Fam. Metotonruipa, MacLeay. 
Genus Ancistrosoma!, 
Antenne in utroque sexu similes, maris paulo majores, in clypei basin ante oculos in- 
serte, capite breviores, pilose, clavate, 9-articulate, articulo basali longo, crasso, 
clavato, pilosissimo, secundo parvo, tertio tribus sequentibus longiore, his sub- 
obovatis, sexto majore et subcyathiformi, tribus apicalibus clavam lamellosam me- 
diocrem efformantibus. 
Labrum transversum, semiovatum, crassum, setosum, in medio leviter emarginatum. 
Mandibule subsimiles, ad basin crass, disco circulari plano, transversim sulcato, apice 
elongato, fortiter incurvato, obtuso et leviter bidentato, externé pilose, margine 
interno membranaceo, dens ciliato. 
Mazille similes, dentibus quinque validis, lobi interioris apice sextum simulante. Palpi 
maxillares breves, 4-articulati, articulo basali reliquis minore, secundo clavato ter- 
tio longiore, hoc obtrigono piloso, quarto majore, ovato-conico. 
Mentum concavum, pilosum, orbiculari-quadratum, in medio angulatum. 
Labium breve, corneum, transversum, leviter emarginatum, ciliatum. Palpi labiales 
parvi, ad labii basin utrinque inserti, 3-articulati, articulo basali subgloboso, minu- 
tissimo, secundo paulo majore, tertio duplo longiore, elliptico, gracili. 
Caput suborbiculare : clypeus incrassatus, ad apicem recurvus, maris profundé fceminz 
leviter in medio emarginatus: oculi parvi, ovati, laterales, verticales, anticé emarginati. 
Thorax convexus, marginatus, hexagonus (preesertim in mare), ad angulos anteriores 
productus, angulis posterioribus subacuminatis, dente brevi in baseos medio lateribus- 
'"Aykcarpov, hamus; copa, corpus. 
