Trigonia aliformis var. attenuata Lycett, 1875 † accepted as Eurotrigonia attenuata (Lycett, 1875) † (original description)
Trigonia beesleyana Lycett, 1874 † accepted as Psilotrigonia beesleyana (Lycett, 1874) † (original description)
Trigonia bella Lycett, 1877 † (original description)
Trigonia blakei Lycett, 1879 † (original description)
Trigonia brodiei Lycett, 1877 † (original description)
Trigonia complanata Lycett, 1872 † (original description)
Trigonia costata var. lata Lycett, 1875 † (original description)
Trigonia costigera Lycett, 1879 † accepted as Apiotrigonia costigera (Lycett, 1979) † (original description)
Trigonia crenulifera Lycett, 1877 † accepted as Praescabrotrigonia crenulifera (Lycett, 1877) † (original description)
Trigonia culleni Lycett, 1877 † accepted as Cotswoldella culleni (Lycett, 1877) † (original description)
Trigonia cunningtoni Lycett, 1875 † accepted as Oistotrigonia cunningtoni (Lycett, 1875) † (original description)
Trigonia daedalea var. confusa Lycett, 1875 † accepted as Neoquadratotrigonia confusa (Lycett, 1875) † (original description)
Trigonia debilis Lycett, 1877 † accepted as Lycettitrigonia debilis (Lycett, 1877) † (original description)
Trigonia dunscombensis Lycett, 1877 † accepted as Lycettitrigonia dunscombensis (Lycett, 1877) † (original description)
Trigonia elongata var. angustata Lycett, 1877 † (original description)
Trigonia elongata var. lata Lycett, 1877 † (original description)
Trigonia etheridgei Lycett, 1875 † accepted as Notoscabrotrigonia etheridgei (Lycett, 1875) † (original description)
Trigonia exaltata Lycett, 1877 † accepted as Myophorella exaltata (Lycett, 1877) † (original description)
Trigonia fimbriata Lycett, 1877 † (original description)
Trigonia forbesii Lycett, 1875 † accepted as Linotrigonia forbesii (Lycett, 1875) † (original description)
Trigonia formosa var. lata Lycett, 1877 † (original description)
Trigonia gemmata var. bifera Lycett, 1879 † accepted as Orthotrigonia bifera (Lycett, 1879) † (original description)
Trigonia griesbachi Lycett, 1872 † accepted as Orthotrigonia griesbachi (Lycett, 1872) † (original description)
Trigonia guisei Lycett, 1883 † (original description)
Trigonia hemisphaerica var. gregaria Lycett, 1877 † accepted as Cotswoldella hemisphaerica (Lycett, 1853) † (original description)
Trigonia hudlestoni Lycett, 1877 † (original description)
Trigonia infracostata Lycett, 1881 † (original description)
Trigonia ingens Lycett, 1872 † accepted as Myophorella intermedia (Fahrenkohl, 1844) † (original description)
Trigonia joassi Lycett, 1874 † (original description)
Trigonia juddiana Lycett, 1872 † (original description)
Trigonia keepingi Lycett, 1877 † accepted as Myophorella keepingi (Lycett, 1877) † (original description)
Trigonia laeviuscula Lycett, 1875 † accepted as Lycettitrigonia laeviuscula (Lycett, 1875) † (original description)
Trigonia leckenbyi Lycett, 1874 † (original description)
Trigonia manseli Lycett, 1874 † accepted as Laevitrigonia manseli (Lycett, 1874) † (original description)
Trigonia meyeri Lycett, 1875 † accepted as Noelmorrisia meyeri (Lycett, 1875) † (original description)
Trigonia moretoni var. oxoniensis Lycett, 1883 † (original description)
Trigonia moutierensis Lycett, 1872 † accepted as Neustriella moutierensis (Lycett, 1872) † (original description)
Trigonia nodosa var. orbignyana Lycett, 1875 † accepted as Quadratotrigonia orbignyana (Lycett, 1875) † (original description)
Trigonia oviedensis Lycett, 1881 † (original description)
Trigonia painei Lycett, 1874 † (original description)
Trigonia parcinoda Lycett, 1872 † accepted as Retetrigonia parcinoda (Lycett, 1872) † (original description)
Trigonia paucicosta Lycett, 1874 † (original description)
Trigonia recticosta Lycett, 1872 † accepted as Orthotrigonia recticosta (Lycett, 1872) † (original description)
Trigonia scabricola Lycett, 1875 † accepted as Notoscabrotrigonia scabricola (Lycett, 1875) † (original description)
Trigonia sculpta var. cheltensis Lycett, 1877 † (original description)
Trigonia sharpiana Lycett, 1874 † (original description)
Trigonia signata var. decurtata Lycett, 1883 † (original description)
Trigonia signata var. rugulosa Lycett, 1883 † (original description)
Trigonia signata var. stutterdi Lycett, 1883 † (original description)
Trigonia signata var. zietenii Lycett, 1883 † (original description)
Trigonia snaintonensis Lycett, 1877 † accepted as Orthotrigonia snaintonensis (Lycett, 1877) † (original description)
Trigonia spinosa var. subovata Lycett, 1877 † accepted as Oistotrigonia subovata (Lycett, 1877) † (original description)
Trigonia tealbyensis Lycett, 1875 † accepted as Pseudomyophorella tealbyensis (Lycett, 1875) † (original description)
Trigonia tenuitexta Lycett, 1874 † (original description)
Trigonia upwarensis Lycett, 1875 † accepted as Oistotrigonia upwarensis (Lycett, 1875) † (original description)
Trigonia vectiana Lycett, 1875 † accepted as Eurotrigonia vectiana (Lycett, 1875) † (original description)
Trigonia vicaryana Lycett, 1875 † accepted as Oistotrigonia vicaryana (Lycett, 1875) † (original description)
Trigonia walfordi Lycett, 1883 † (original description)
Trigonia williamsoni Lycett, 1874 † (original description)
Trigonia windoesi Lycett, 1883 † (original description)
Trigonia witchelli Lycett, 1877 † (original description)
Trigonia woodwardi Lycett, 1872 † (original description)