of the Amazon Valley. 281 



subelliptical and depressed, the tips obliquely sinuate-truncate ; 

 the centro-basal ridge slightly elevated and crowned with blackish 

 hairs ; the basal half of the surface is punctured, and the colour 

 is the same as that of the head and thorax, but varied with small 

 olive-brown specks placed partly in rows, and an undulated 

 fascia of the same behind the middle interrupted at the suture. 

 Body beneath and legs yellowish testaceous, thinly clothed with 

 ashy pile ; apex of femora and tibise and middle part of the 

 tarsi blackish. 



Taken on dead slender branches at Santarem and on the 

 banks of the Tapajos. At Villa Nova, on the banks of the 

 Lower Amazons, I obtained one example, which differs consider- 

 ably in colour from the Tapajos form. This may be called 



Local var. 0. pallipes. Same size and shape as the type. 

 General colour tawny ashy. Antennae with the basal joint red- 

 dish, the remaining joints dusky, with the basal portions of the 

 third, fourth, sixth, eighth, and following joints clear pale testa- 

 ceous. The disk of the thorax has several olive-brown spots. 

 The elytra are of a reddish-tawny hue, with tawny-ashy pile ; 

 they are spotted as in the typical 0. cinerascens, but instead of 

 a waved fascia behind the middle, they have simply a short 

 oblique stripe on the disk of each. Body beneath and legs 

 pale testaceous ; knees, tips of tibise, and middle of the tarsi 

 dusky. 



O. cinerascens resembles much in markings a small allied 

 species from Rio Janeiro, which is as yet unnamed in collec- 

 tions *. 



* 0. ignohilis, n. sp. — Parvus, subellipticus, olivaeeo-cinereus fusco va- 

 riegatus. Caput fuscum. Antennae rufo-picese, articulis (duobus 

 basalibus exceptis) apice nigris. Thorax olivaceus, spinis lateralibus 

 longioribus acutissimis, prope angulos posteriores sitis. Elytra sub- 

 depressa, apice peroblique sinuato-truncata, angulis extenais longe 

 mucronatis, carinis centrobasalibus longe nigro penicillatis ; dorso 

 punctata, cinereo-olivacea, maculis minutis fasciaque lata pone medium 

 fuscis. Corpus subtus nigrum. Pedes nigricantes ; femoribus, tibiis 

 tarsisque dimidiis basalibus testaceis. Long. 2 lin. Hub. Rio Ja- 

 neiro. Coll. Bakewell, Bates. 



A very pretty species of this genus, captured near Rio Janeiro, by Squires, 

 in some number, is 



O. rotundicollis. — Oblongus, latiusculus, depressus, cinereus, griseus 

 vel fulvus, cano fuscoque variegatus. Antennae rufescentes, articulis 

 (duobus basalibus exceptis) apice nigris. Thorax brevis, latus, lateri- 

 bus ante medium dilatato-rotundatis, utrinque spina minuta distincta 

 ab angulo postico distante ; dorso punctato, nigro bimaculato, lateri- 

 bus (infra spinam) plaga fusca cum vitta basali elytrorum conjuncta 

 notatis. Elytra subtrigona, depressa, apice peroblique sinuato- 

 truncata, angulis externis longe mucronatis, carinis centrobasalibus 

 brevibus, carinis lateralibus acutis ; dorso punctato, griseo vel fulvo, 



Ann. ^ Mag, N. Hist, Ser. 3. Vol, xii. 19 



