| Orectochilus mjobergianus | Orectochilus murinus | Orectochilus murudensis |
| Orectochilus musculus | Orectochilus nathani | Orectochilus neglectus |
| Orectochilus nigricans | Orectochilus nigroaeneus | Orectochilus nipponensis |
| Orectochilus nitens | Orectochilus nuristanicus | Orectochilus oberthueri |
| Orectochilus oblongiusculus | Orectochilus obscuriceps | Orectochilus obtusangulus |
| Orectochilus obtusipennis | Orectochilus orbisonorum | Orectochilus orissaensis |
| Orectochilus ornaticollis | Orectochilus oxygonus | Orectochilus palawanensis |
| Orectochilus palliatus | Orectochilus panoembanganus | Orectochilus patellimanus |
| Orectochilus pendleburyi | Orectochilus pescheti | Orectochilus pfisteri |
| Orectochilus philippinarum | Orectochilus pilosellus | Orectochilus planatus |
| Orectochilus planiusculus | Orectochilus procerus | Orectochilus productus |
| Orectochilus pubescens | Orectochilus pulchellus | Orectochilus punctilabris |
| Orectochilus punctipennis | Orectochilus punctulatus | Orectochilus pusillus |
| Orectochilus regimbarti | Orectochilus ribeiroi | Orectochilus ritsemae |
| Orectochilus rivularis | Orectochilus ruficaudatus | Orectochilus samarensis |
| Orectochilus scalaris | Orectochilus schillhammeri | Orectochilus schultzei |
| Orectochilus sculpturatus | Orectochilus seminitens | Orectochilus semivestitus |
| Orectochilus severini | Orectochilus similis | Orectochilus sinhalensis |
| Orectochilus spiniger | Orectochilus spinosus | Orectochilus staudingeri |
| Orectochilus strandi | Orectochilus striolifer | Orectochilus sublineatus |
| Orectochilus subsinuatus | Orectochilus sulcipennis | Orectochilus sutteri |
| Orectochilus teranishii | Orectochilus tibialis | Orectochilus timorensis |
| Orectochilus tomentosus | Orectochilus tonkinensis | Orectochilus trianguliger |
| Orectochilus undulans | Orectochilus validus | Orectochilus velatus |
| Orectochilus vestitus | Orectochilus villosovittatus | Orectochilus villosus |
| Orectochilus vitalisi | Orectochilus volubilis | Orectochilus wangi |
| Orectochilus waterstradti | Orectochilus wehnckei | Orectochilus wui |
| Orectochilus yayeyamensis | Orectochilus zeravschanicus | Orectogyrus |
| Orectogyrus albertianus | Orectogyrus alluaudi | Orectogyrus angularis |
| Orectogyrus argenteovittatus | Orectogyrus assimilis | Orectogyrus aureovittatus |
| Orectogyrus aureus | Orectogyrus baguenai | Orectogyrus barrosmachadoi |
| Orectogyrus basilewskyi | Orectogyrus bedeli | Orectogyrus bicostatus |
| Orectogyrus buettikoferi | Orectogyrus burgeoni | Orectogyrus camerunensis |
| Orectogyrus capicolus | Orectogyrus centralis | Orectogyrus coerulescens |
| Orectogyrus collarti | Orectogyrus conjugens | Orectogyrus constrictus |
| Orectogyrus convexus | Orectogyrus coptogynus | Orectogyrus costatus |
| Orectogyrus cuprifer | Orectogyrus curvipes | Orectogyrus cyanicollis |
| Orectogyrus cyanipterus | Orectogyrus dahomeensis | Orectogyrus decorsei |
| Orectogyrus dedalus | Orectogyrus demeryi | Orectogyrus dimidiatus |
| Orectogyrus discors | Orectogyrus dorsiger | Orectogyrus dunkeli |
| Orectogyrus elongatus | Orectogyrus endroedyi | Orectogyrus erosus |
| Orectogyrus escherichi | Orectogyrus eversor | Orectogyrus familiaris |
| Orectogyrus favareli | Orectogyrus feminalis | Orectogyrus ferranti |
| Orectogyrus fluviatilis | Orectogyrus formosus | Orectogyrus furcatus |
| Orectogyrus fusciventris | Orectogyrus gigas | Orectogyrus glaucus |
| Orectogyrus grandis | Orectogyrus grisescens | Orectogyrus guignoti |
| Orectogyrus hancocki | Orectogyrus hastatus | Orectogyrus hawashensis |
| Orectogyrus heros | Orectogyrus imitans | Orectogyrus interstitialis |
| Orectogyrus jucundus | Orectogyrus kasikiensis | Orectogyrus kaszabi |
| Orectogyrus kelleni | Orectogyrus kutteri | Orectogyrus lanceolatus |
| Orectogyrus laticostis | Orectogyrus latiusculus | Orectogyrus leroyi |
| Orectogyrus lionotus | Orectogyrus longilabris | Orectogyrus longitaris |
| Orectogyrus luayensis | Orectogyrus lujai | Orectogyrus lunai |
| Orectogyrus luteolus | Orectogyrus madagascariensis | Orectogyrus manensis |
| Orectogyrus masculinus | Orectogyrus mesochlorus | Orectogyrus milliaui |
| Orectogyrus mirabilis | Orectogyrus mocquerysi | Orectogyrus monardi |
| Orectogyrus nairobiensis | Orectogyrus nanus | Orectogyrus neumanni |
| Orectogyrus noctuabundus | Orectogyrus oberthueri | Orectogyrus obscurus |
| Orectogyrus ochsi | Orectogyrus orectochilinus | Orectogyrus orientalis |
| Orectogyrus ornaticollis | Orectogyrus oscari | Orectogyrus oscaris |
| Orectogyrus overlaeti | Orectogyrus pallidiventris | Orectogyrus pallidocinctus |
| Orectogyrus pamelae | Orectogyrus paradoxus | Orectogyrus patromimus |
| Orectogyrus peridines | Orectogyrus perrieri | Orectogyrus petrinus |
| Orectogyrus pictimanus | Orectogyrus polli | Orectogyrus posticalis |
| Orectogyrus potamophilus | Orectogyrus probus | Orectogyrus prolongatus |
| Orectogyrus pulcherrimus | Orectogyrus purpureus | Orectogyrus rhodesianus |
| Orectogyrus riggenbachi | Orectogyrus robustus | Orectogyrus rotundatus |
| Orectogyrus rugulifer | Orectogyrus rugulosus | Orectogyrus rustibus |
| Orectogyrus ruwenzoricus | Orectogyrus schistaceus | Orectogyrus schoenherri |
| Orectogyrus schubotzi | Orectogyrus schultzei | Orectogyrus semisericeus |
| Orectogyrus semivillosus | Orectogyrus sericeus | Orectogyrus sexualis |
| Orectogyrus simulans | Orectogyrus sjoestedti | Orectogyrus socius |
| Orectogyrus specularis | Orectogyrus speculum | Orectogyrus spinifer |
| Orectogyrus strigicollis | Orectogyrus subseriatus | Orectogyrus tavetensis |
| Orectogyrus trilobatus | Orectogyrus uellensis | Orectogyrus vagus |
| Orectogyrus vanstraeleni | Orectogyrus vedyi | Orectogyrus venustulus |
| Orectogyrus vermiculatus | Orectogyrus vestitus | Orectogyrus vicinus |
| Orectogyrus virescens | Orectogyrus walterrossii | Orectogyrus witteanus |
| Orectogyrus zimmermanni | Orectolobidae | Orectolobiformes |
| Orectolobus | Orectolobus halei | Orectolobus japonicus |
| Orectolobus maculatus | Orectospira | Orectospira shikoensis |
| Orectospira tectiformis | Oregano | Oregocerata |
| Oregon | Oregon (định hướng) | Oregon (làng thuộc quận Dane, Wisconsin) |
| Oregon (thị trấn thuộc quận Dane, Wisconsin) | Oregon (thị trấn), Quận Dane, Wisconsin | Oregon City (lớp tàu tuần dương) |
| Oregon City, OR | Oregon City, Oregon | Oregon State University |
| Oregon, Illinois | Oregon, My Oregon | Oregon, Ohio |
| Oregon, Quận Washington, Iowa | Oregon, Quận Wayne, Pennsylvania | Oregon-grape |
| Oregon-Nashua, Quận Ogle, Illinois | Oregonichthys crameri | Oregonichthys kalawatseti |
| Oregoniscus nearcticus | Oregostoma bipartitum | Oregostoma nigripes |
| Oregostoma nitidiventre | Oregostoma puniceum | Oregramma gloriosum |
| Oreiallagma acutum | Oreiallagma oreas | Oreiallagma prothoracicum |
| Oreiallagma quadricolor | Oreiallagma thelkterion | Oreilla |
| Oreina | Oreina alpestris | Oreina bidentata |
| Oreina bifrons | Oreina cacaliae | Oreina caerulea |
| Oreina canavesei | Oreina collucens | Oreina elongata |
| Oreina fairmairiana | Oreina frigida | Oreina ganglbaueri |
| Oreina genei | Oreina gloriosa | Oreina intricata |
| Oreina liturata | Oreina ludovicae | Oreina melancholica |
| Oreina peirolerii | Oreina pennina | Oreina plagiata |
| Oreina redikorzevi | Oreina sibylla | Oreina speciosa |
