Amazonian Prionides, 
41 
Genus Oethomegas. 
Serville, Ann. Soc. Ent, Fr. 1832^ p. 149. 
1. Ortliomegas cinnamoneus. 
Lin. Syst. I'I’at. ii. 623; Drury, 111. i. 89. t. 40. f. 2, $ . 
0. oblongo-linearis, cinnamoneus, aureo-fulvo sericeus, 
Isevis; tliorace lateribus pone medium dente magno 
oblique, antice denticulis duobus vel tribus armato. 
Long. 22-30 lin. ( ,^ , $ ). 
Found occasionally, in repose on leaves in the forest, 
throughout the Amazons region. 
Genus Macrodontia. 
Serville, Ann. Soc. Ent. Fr. 1832, p. 140. 
1. Macrodontia cervicornis, 
Lin. Mus. Lud. Ulr. p. 65 ; Oliv. Ent. 66, pi. 2, f. 8. 
M. magna, depressa, rufo nigroque varia, elytris flavo- 
rufis, lineis plagisque nigris variegatis. 
Long. unc. 24-4. (8", $ .) 
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, ? . 
S . 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 desun t) 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 longitudinali 
lineisque aliquot elevatis nitidis, sparsim punctatis. 
Elytra marginibus pone humeros valde explanatis, 
margine foliaceo usque ad apicem extenso sed sensim 
