Amazonian Prionides. 41 



Genus Orthomegas. 

 Serville, Ann. Soc. Ent. Fr. 1832, p. 149. 



1. Orthomegas cmnamoneus. 

 Lin. Syst. Nat. ii. 623; Drury, 111. i. 89. t. 40. f. 2, ? . 



0. oblongo-linearis, cinnamoneus, aureo-fulvo sericeus, 

 laevis ; thorace lateribus pone medium dente magno 

 obliquo, antice denticulis duobus vel tribus armato. 



Long. 22-30 lin. {$ , ? ). 



Found occasionally, in repose on leaves in the forest, 

 throughout the Amazons region. 



Genus Mackodontia. 

 Serville, Ann. Soc. Ent. Fr. 1832, p. 140. 



1. Macrodontia cervicornis. 

 Lin. Mus. Lud. Ulr. p. 65 ; Oliv. Ent. 66, jdI. 2, f. 8. 



M. magna, depressa, rufo nigroque varia, elytris flavo- 



rufis, lineis plagisque nigris variegatis. 

 Long. unc. 24-4. {^, ? .) 



A rare insect on the Amazons ; on dead trees, banks 

 of the Tapajos, and at Ega. 



2. Macrodontia crenata. 

 Oliv. Ent. 66. p. 27, pi. 12. f. 45, $ . 



c?. A $ differt spina anteriore thoracis brevissima, 

 et mandibulis multo longioribus. Oblonga, depressa, 

 fusco-castanea, elytris cinnamoneis. Caput supra 

 concavum, grosse punctatum, mandibulis capite ses- 

 qui longioribus, triquetris, cum antennarum basi (ar- 

 ticuli reliqui desunt) nigris. Thorax transversus, 

 quadratus, basi valde angustatus, lateribus inter spi- 

 nas rectis, crenulatis, angulo antico spina minuta 

 acuta oblique antrorsum spectante armato, spina pos- 

 tica majore sed brevi, angulis posticis distinctis acutis ; 

 supra creberrime punctatus, medio plaga longitudinal! 

 lineisque aliquot elevatis nitidis, sparsim punctatis. 

 Elytra marginibus pone humeros valde explanatis, 

 margine foliaceo usque ad apicem extenso sed sensim 



