| Orectochilus helferi | Orectochilus himalayensis | Orectochilus hirtellus |
| Orectochilus horni | Orectochilus indicus | Orectochilus indulans |
| Orectochilus jaechi | Orectochilus javanus | Orectochilus jilanzhui |
| Orectochilus kempi | Orectochilus kinabaluensis | Orectochilus klapperichi |
| Orectochilus klynstrai | Orectochilus landaisi | Orectochilus laticinctus |
| Orectochilus latimanus | Orectochilus limbatus | Orectochilus longulus |
| Orectochilus lucidus | Orectochilus lumbaris | Orectochilus malaisei |
| Orectochilus marginepennis | Orectochilus matruelis | Orectochilus melli |
| Orectochilus metallicus | Orectochilus mimicus | Orectochilus minusculus |
| Orectochilus mjobergi | 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 |
