- family cryptobranchidae
- family cryptocercidae
- family cryptogrammataceae
- family ctenizidae
- family cuculidae
- family cucurbitaceae
- family culicidae
- family cunoniaceae
- family cupressaceae
- family curculionidae
- family cuterebridae
- family cyatheaceae
- family cycadaceae
- family cyclopteridae
- family cymatiidae
- family cynipidae
- family cynocephalidae
- family cynoglossidae
- family cyperaceae
- family cypraeidae
- family cyprinidae
- family cyprinodontidae
- family cyrilliaceae
- family dacninae
- family dacrymycetaceae
- family dactylopiidae
- family dactylopteridae
- family dactyloscopidae
- family danaidae
- family dasyatidae
- family dasypodidae
- family dasyproctidae
- family dasyuridae
- family dasyurinae
- family daubentoniidae
- family davalliaceae
- family delphinidae
- family dematiaceae
- family dendrocolaptidae
- family dennstaedtiaceae
- family dermestidae
- family dermochelyidae
- family desmidiaceae
- family desmodontidae
- family diapensiaceae
- family diaspididae
- family dicamptodontidae
- family dicksoniaceae
- family dicranaceae
- family didelphidae
- family dilleniaceae
- family dinornithidae
- family diodontidae
- family diomedeidae
- family dioscoreaceae
- family dipodidae
- family dipsacaceae
- family dipterocarpaceae
- family discoglossidae
- family doctor
- family doliolidae
- family dracunculidae
- family drepanididae
- family dromaeosauridae
- family droseraceae
- family drosophilidae
- family dryopteridaceae
- family dugongidae
- family dytiscidae
- family ebenaceae
- family echeneidae
- family echeneididae
- family edaphosauridae
- family eimeriidae
- family elaeagnaceae
- family elaeocarpaceae
- family elapidae
- family elateridae
- family electrophoridae
- family eleotridae
- family elephantidae
- family elopidae
- family embiotocidae
- family empetraceae
- family emydidae
- family endamoebidae
- family engraulidae
- family enterobacteriaceae
- family entolomataceae
- family entomophthoraceae
- family epacridaceae
- family ephedraceae
- family ephemeridae
- family ephippidae
- family equidae
- family equisetaceae
- family erethizontidae
- family ericaceae
- family erinaceidae
- family eriocaulaceae
- family erysiphaceae
- family erythroxylaceae
- family eschrichtiidae
- family esocidae
- family euglenaceae
- family euphorbiaceae
- family eurylaimidae
- family exocoetidae
- family fabaceae
- family fagaceae
- family falconidae
- family fasciolidae
- family felidae
- family filariidae
- family fissurellidae
- family fistulariidae
- family fistulinaceae
- family flacourtiaceae
- family forficulidae
- family formicariidae
- family formicidae
- family fouquieriaceae
- family fregatidae
- family fringillidae
- family fucaceae
- family fulgoridae
- family fumariaceae
- family funkaceae
- family furnariidae
- family gadidae
- family galbulidae
- family gasterophilidae
- family gasterosteidae
- family gavialidae
- family gavidae
- family geastraceae
- family gekkonidae
- family gelechiidae
- family gempylidae
- family gentianaceae
- family geoglossaceae
- family geometridae
- family geomyidae
- family geophilidae
- family geraniaceae
- family gerreidae
- family gerridae
- family gerrididae
- family gesneriaceae
- family gigartinaceae
- family ginkgoaceae
- family giraffidae
- family glareolidae
- family gleicheniaceae
- family gliridae
- family globigerinidae
- family glossinidae
- family gnetaceae
- family gobiesocidae
- family gobiidae
- family gomphotheriidae
- family gonorhynchidae
- family goodeniaceae
- family gracilariidae
- family graminaceae
- family gramineae
- family grossulariaceae
- family gruidae
- family gryllidae
- family guttiferae
- family gyrinidae
- family hadrosauridae
- family haematopodidae
- family haemodoraceae
- family haemoproteidae
- family haemulidae
- family halictidae
- family haliotidae
- family haloragaceae
- family haloragidaceae
- family hamamelidaceae
- family helicidae
- family helodermatidae
- family helotiaceae
- family helvellaceae
- family hemerobiidae
- family hemerocallidaceae
- family hemiprocnidae
- family hemiramphidae
- family heteromyidae
- family hexagrammidae
- family hexanchidae
- family hippoboscidae
- family hippocastanaceae
- family hippopotamidae
- family hipposideridae
- family hirudinidae
- family hirundinidae
- family history
- family holocentridae