| colletes hederae | Yes | species | eukaryota | invertebrates | species | 338708 | click here |
| colobanthus quitensis | Yes | species | eukaryota | plants | species | 552857 | click here |
| colocasia esculenta | Yes | species | eukaryota | plants | species | 4460 | click here |
| cololabis saira | Yes | species | eukaryota | vertebrates | species | 129043 | click here |
| colopha kansugei | Yes | species | eukaryota | invertebrates | species | 372563 | click here |
| colopha ulmicola | Yes | species | eukaryota | invertebrates | species | 527608 | click here |
| colophina arctica | Yes | species | | | species | 1244017 | click here |
| colophospermum mopane | Yes | species | eukaryota | plants | species | 162715 | click here |
| colostethus panamansis | Yes | species | eukaryota | vertebrates | species | 384868 | click here |
| colpophyllia natans | Yes | species | eukaryota | invertebrates | species | 242718 | click here |
| columba livia | Yes | species | eukaryota | vertebrates | species | 8932 | click here |
| columba palumbus | Yes | species | eukaryota | vertebrates | species | 8934 | click here |
| columba sp. | Yes | no rank | eukaryota | vertebrates | species | 8933 | click here |
| columbicola columbae | Yes | species | eukaryota | invertebrates | species | 128991 | click here |
| columbidae | Yes | | | vertebrates | family | 8930 | click here |
| columbina passerina | Yes | species | eukaryota | vertebrates | species | 111974 | click here |
| columbina talpacoti | Yes | species | eukaryota | vertebrates | species | 504887 | click here |
| combretum molle | Yes | species | eukaryota | plants | species | 507414 | click here |
| conocarpus erectus | Yes | species | eukaryota | plants | species | 134917 | click here |
| conolophus subcristatus | Yes | species | eukaryota | vertebrates | species | 31140 | click here |
| conomelus anceps | Yes | species | eukaryota | invertebrates | species | 491269 | click here |
| convolvulus arvensis | Yes | species | eukaryota | plants | species | 4123 | click here |
| conyza canadensis | Yes | species | eukaryota | plants | species | 72917 | click here |
| coptosoma japonicum | Yes | species | eukaryota | invertebrates | species | 355288 | click here |
| coptosoma parvipictum | Yes | species | eukaryota | invertebrates | species | 355286 | click here |
| coptosoma sphaerula | Yes | species | eukaryota | invertebrates | species | 355287 | click here |
| coptotermes curvignathus | Yes | species | eukaryota | invertebrates | species | 270671 | click here |
| coptotermes formosanus | Yes | species | eukaryota | invertebrates | species | 36987 | click here |
| coragyps atratus | Yes | species | eukaryota | vertebrates | species | 33614 | click here |
| corallorhiza trifida | Yes | species | eukaryota | plants | species | 451881 | click here |
| corchorus capsularis | Yes | species | eukaryota | plants | species | 210143 | click here |
| corcyra cephalonica | Yes | species | eukaryota | invertebrates | species | 139036 | click here |
| cordyline fruticosa | Yes | species | eukaryota | plants | species | 39501 | click here |
| coregonus lavaretus | Yes | species | eukaryota | vertebrates | species | 59291 | click here |
| coregonus migratorius | Yes | species | eukaryota | vertebrates | species | 884168 | click here |
| coregonus peled | Yes | species | eukaryota | vertebrates | species | 107322 | click here |
| coriandrum sativum | Yes | species | eukaryota | plants | species | 4047 | click here |
| correlophus ciliatus | Yes | species | eukaryota | vertebrates | species | 143539 | click here |
| cortinarius armillatus | Yes | species | eukaryota | plants | species | 70562 | click here |
| cortinarius caperatus | Yes | species | eukaryota | plants | species | 75324 | click here |
| corvus | Yes | | | vertebrates | genus | 30420 | click here |
| corvus brachyrhynchos | Yes | species | eukaryota | vertebrates | species | 85066 | click here |
| corvus cornix | Yes | species | eukaryota | vertebrates | species | 181096 | click here |
| corvus corone | Yes | species | eukaryota | vertebrates | species | 30422 | click here |
| corvus coronoides | Yes | species | eukaryota | vertebrates | species | 108826 | click here |
| corvus frugilegus | Yes | species | eukaryota | vertebrates | species | 75140 | click here |
| corvus macrorhynchos | Yes | species | eukaryota | vertebrates | species | 36249 | click here |
| corvus splendens | Yes | species | eukaryota | vertebrates | species | 701737 | click here |
| corylus avellana | Yes | species | eukaryota | plants | species | 13451 | click here |
| corynorhinus townsendii | Yes | species | eukaryota | mammals | species | 124745 | click here |
| coryphaena hippurus | Yes | species | eukaryota | vertebrates | species | 34814 | click here |
| coscinium fenestratum | Yes | species | eukaryota | plants | species | 483232 | click here |
| cosmos bipinnatus | Yes | species | eukaryota | plants | species | 51277 | click here |
| costelytra zealandica | Yes | species | eukaryota | invertebrates | species | 50579 | click here |
| cotesia flavipes | Yes | species | eukaryota | invertebrates | species | 89805 | click here |
| cotesia vestalis | Yes | species | eukaryota | invertebrates | species | 217443 | click here |
| cotinus coggygria | Yes | species | eukaryota | plants | species | 269719 | click here |
| cotoneaster | Yes | | | plants | genus | 36607 | click here |
| coturnix | Yes | | | vertebrates | genus | 9090 | click here |
| coturnix chinensis | Yes | species | eukaryota | vertebrates | species | 46218 | click here |
| coturnix coturnix | Yes | species | eukaryota | vertebrates | species | 9091 | click here |
| coturnix japonica | Yes | species | eukaryota | vertebrates | species | 93934 | click here |
| crassostrea | Yes | | | invertebrates | genus | 6564 | click here |
| crassostrea gigas | Yes | species | eukaryota | invertebrates | species | 29159 | click here |
| crassostrea iredalei | Yes | species | eukaryota | invertebrates | species | 167541 | click here |
| crassula capitella | Yes | species | eukaryota | plants | species | 306412 | click here |
| crataegus | Yes | | | plants | genus | 23159 | click here |
| crataegus mollis | Yes | species | eukaryota | plants | species | 36593 | click here |
| crataegus monogyna | Yes | species | eukaryota | plants | species | 140997 | click here |
| crataerina melbae | Yes | species | | | species | 526368 | click here |
| crataerina pallida | Yes | species | eukaryota | invertebrates | species | 452744 | click here |
| craugastor crassidigitus | Yes | species | eukaryota | vertebrates | species | 228433 | click here |
| craugastor melanostictus | Yes | species | eukaryota | vertebrates | species | 449771 | click here |
| craugastor ranoides | Yes | species | eukaryota | vertebrates | species | 228432 | click here |
| crax blumenbachii | Yes | species | eukaryota | vertebrates | species | 125061 | click here |
| cricetidae | Yes | | | rodents | family | 337677 | click here |
| cricetinae | Yes | | | rodents | subfamily | 10026 | click here |
| cricetulus griseus | Yes | species | eukaryota | rodents | species | 10029 | click here |
| cricetulus migratorius | Yes | species | eukaryota | rodents | species | 10032 | click here |
| crocodylus | Yes | | | vertebrates | genus | 8500 | click here |
| crocodylus niloticus | Yes | species | eukaryota | vertebrates | species | 8501 | click here |
| crocodylus palustris | Yes | species | eukaryota | vertebrates | species | 184238 | click here |
| crocodylus siamensis | Yes | species | eukaryota | vertebrates | species | 68455 | click here |
| crocus sativus | Yes | species | eukaryota | plants | species | 82528 | click here |
| crocuta crocuta | Yes | species | eukaryota | mammals | species | 9678 | click here |
| crotalaria | Yes | | | plants | genus | 3828 | click here |
| crotalaria burhia | Yes | species | | | species | 1117112 | click here |
| crotalaria incana | Yes | species | eukaryota | plants | species | 46447 | click here |
| crotalaria pallida | Yes | species | eukaryota | plants | species | 3830 | click here |
| crotalaria spectabilis | Yes | species | eukaryota | plants | species | 517187 | click here |
| crotalaria spinosa | Yes | species | | | species | 1232590 | click here |
| crotalus | Yes | | | vertebrates | genus | 8728 | click here |
| crotalus adamanteus | Yes | species | eukaryota | vertebrates | species | 8729 | click here |
| crotalus atrox | Yes | species | eukaryota | vertebrates | species | 8730 | click here |
| crotalus durissus | Yes | species | eukaryota | vertebrates | species | 8731 | click here |
| crotalus durissus cumanensis | Yes | subspecies | eukaryota | vertebrates | subspecies | 184542 | click here |
| crotalus durissus terrificus | Yes | subspecies | eukaryota | vertebrates | subspecies | 8732 | click here |
| crotalus oreganus | Yes | species | eukaryota | vertebrates | species | 332624 | click here |
| crotalus oreganus abyssus | Yes | subspecies | eukaryota | vertebrates | subspecies | 128077 | click here |
| crotalus ruber | Yes | species | eukaryota | vertebrates | species | 8735 | click here |