Opinions from G. A. Cooper and R. E. Grant 1974
- 'Acanthocrania alta belongs to Acanthocrania'
- 'Acanthocrania conferta belongs to Acanthocrania'
- 'Acanthocrania densispina belongs to Acanthocrania'
- 'Acanthocrania intermedia belongs to Acanthocrania'
- 'Acanthocrania magna belongs to Acanthocrania'
- 'Acanthocrania minutispinosa belongs to Acanthocrania'
- 'Acanthocrania platys belongs to Acanthocrania'
- 'Acanthocrania regularis belongs to Acanthocrania'
- 'Acanthocrania vasta belongs to Acanthocrania'
- 'Adriana guadalupensis is recombined as Pseudoleptodus guadalupensis'
- 'Bothrostegium compactum belongs to Bothrostegium'
- 'Bothrostegium derbyoideum belongs to Bothrostegium'
- 'Bothrostegium pusillum belongs to Bothrostegium'
- 'Chelononia neali belongs to Chelononia'
- 'Chelononia straminea belongs to Chelononia'
- 'Choanodus anomalus belongs to Choanodus'
- 'Choanodus irregularis belongs to Choanodus'
- 'Choanodus perfectus belongs to Choanodus'
- 'Collemataria batilliformis belongs to Collemataria'
- 'Collemataria elongata belongs to Collemataria'
- 'Collemataria gregaria belongs to Collemataria'
- 'Collemataria irregularis belongs to Collemataria'
- 'Collemataria platys belongs to Collemataria'
- 'Collemataria spatulata belongs to Collemataria'
- 'Coscinophora magnifica belongs to Coscinophora'
- 'Coscinophora monilifera belongs to Coscinophora'
- 'Coscinophora nodosa belongs to Coscinophora'
- 'Derbyia belongs to Derbyiidae'
- 'Derbyia bella belongs to Derbyia'
- 'Derbyia carteri belongs to Derbyia'
- 'Derbyia cincinnata belongs to Derbyia'
- 'Derbyia complicata belongs to Derbyia'
- 'Derbyia crenulata belongs to Derbyia' according to Girty 1909
- 'Derbyia crenulata belongs to Derbyia'
- 'Derbyia elevata belongs to Derbyia'
- 'Derbyia filosa belongs to Derbyia'
- 'Derbyia informis belongs to Derbyia'
- 'Derbyia laqueata belongs to Derbyia'
- 'Derbyia nasuta belongs to Derbyia' according to Girty 1909
- 'Derbyia nasuta belongs to Derbyia'
- 'Derbyia pannucia belongs to Derbyia'
- 'Derbyia profunda belongs to Derbyia'
- 'Derbyia scitula belongs to Derbyia'
- 'Derbyia strophomenoidea belongs to Derbyia'
- 'Derbyia texta belongs to Derbyia'
- 'Derbyoides dunbari belongs to Derbyoides'
- 'Derbyoides marathonensis belongs to Derbyoides'
- 'Diplanus apochordus belongs to Diplanus'
- 'Diplanus catatonus belongs to Diplanus'
- 'Diplanus rarus belongs to Diplanus'
- 'Diplanus redactus belongs to Diplanus'
- 'Eolyttonia catilla belongs to Eolyttonia'
- 'Eolyttonia chaotica belongs to Eolyttonia'
- 'Eolyttonia circularis belongs to Eolyttonia'
- 'Eolyttonia cornucopia belongs to Eolyttonia'
- 'Eolyttonia gigantea belongs to Eolyttonia'
- 'Eolyttonia parviconica belongs to Eolyttonia'
- 'Eolyttonia phialiforma belongs to Eolyttonia'
- 'Eolyttonia pocillata belongs to Eolyttonia'
- 'Eolyttonia progressa belongs to Eolyttonia'
- 'Geyerella americana belongs to Geyerella'
- 'Geyerella americana belongs to Geyerella' according to Girty 1909
- 'Geyerella hessi belongs to Geyerella'
- 'Geyerella inexpectata belongs to Geyerella'
- 'Geyerella kingorum belongs to Geyerella'
- 'Goniarina appeli belongs to Goniarina'
- 'Goniarina diabloensis belongs to Goniarina'
- 'Goniarina futilis belongs to Goniarina'
- 'Goniarina magniextensa belongs to Goniarina'
- 'Goniarina pyelodes belongs to Goniarina'
- 'Goniarina striata belongs to Goniarina'
- 'Hypopsia versuta belongs to Hypopsia'
- 'Isogramma concavum belongs to Isogramma'
- 'Isogramma diabloense belongs to Isogramma'
- 'Isogramma lobatum belongs to Isogramma'
- 'Isogramma vidriense belongs to Isogramma'
- 'Lepidocrania sparsispinosa belongs to Lepidocrania'
- 'Lepidocrania sublamellosa belongs to Lepidocrania'
- 'Lepidocrania tardispinosa belongs to Lepidocrania'
- 'Leptodus americanus belongs to Leptodus' according to Girty 1909
- 'Leptodus americanus is recombined as Collemataria americana'
- 'Leptodus diabloensis is recombined as Eolyttonia diabloensis'
- 'Leptodus guadalupensis belongs to Leptodus' according to Girty 1909
- 'Leptodus marshalli is recombined as Collemataria marshalli'
- 'Loxophragmus ellipticus belongs to Loxophragmus'
- 'Lyttonia hortoni is recombined as Coscinophora hortoni'
- 'Meekella angustiplicata belongs to Meekella'
- 'Meekella attenuata belongs to Meekella'
- 'Meekella attenuata belongs to Meekella' according to Girty 1909
- 'Meekella calathica belongs to Meekella'
- 'Meekella caperata belongs to Meekella'
- 'Meekella circularis belongs to Meekella'
- 'Meekella difficilis belongs to Meekella' according to Girty 1909
- 'Meekella difficilis is a subjective synonym of Meekella skenoides'
- 'Meekella enormis belongs to Meekella'
- 'Meekella globosa is recombined as Niviconia globosa'
- 'Meekella grandis belongs to Meekella' according to King 1931
- 'Meekella grandis is a subjective synonym of Meekella occidentalis'
- 'Meekella hessensis belongs to Meekella' according to King 1931
- 'Meekella hessensis belongs to Meekella'
- 'Meekella intermedia belongs to Meekella'
- 'Meekella magnifica belongs to Meekella'
- 'Meekella prionota belongs to Meekella'
- 'Meekella skenoides belongs to Meekella' according to Girty 1909
- 'Meekella skenoides belongs to Meekella'
- 'Meekella texana belongs to Meekella'
- 'Meekella texana belongs to Meekella' according to King 1931
- 'Niviconia abrupta belongs to Niviconia'
- 'Nothopindax egregius belongs to Nothopindax'
- 'Ombonia invecta belongs to Ombonia'
- 'Orthotetella wolfcampensis belongs to Orthotetella'
- 'Orthotetes campanulatus is a subjective synonym of Geyerella americana'
- 'Orthotetes campanulatus belongs to Orthotetes' according to Girty 1909
- 'Orthotetes declivis belongs to Orthotetes' according to Girty 1909
- 'Orthotetes declivis is a subjective synonym of Orthotetes guadalupensis'
- 'Orthotetes distortus belongs to Orthotetes' according to Girty 1909
- 'Orthotetes distortus is a subjective synonym of Geyerella americana'
- 'Orthotetes guadalupensis belongs to Orthotetes' according to Girty 1909
- 'Orthotetes guadalupensis is recombined as Ombonia guadalupensis'
- 'Parakeyserlingina fredericksi is recombined as Eolyttonia fredericksi'
- 'Paralyttonia girtyi is recombined as Rigbyella girtyi'
- 'Petasmaia expansa belongs to Petasmaia'
- 'Petrocrania diabloensis belongs to Petrocrania'
- 'Petrocrania exasperata belongs to Petrocrania'
- 'Petrocrania septifera belongs to Petrocrania'
- 'Petrocrania teretis belongs to Petrocrania'
- 'Poikilosakos informis belongs to Poikilosakos'
- 'Pseudoleptodus annosus belongs to Pseudoleptodus'
- 'Pseudoleptodus conicus belongs to Pseudoleptodus'
- 'Pseudoleptodus cucullatus belongs to Pseudoleptodus'
- 'Pseudoleptodus getawayensis belongs to Pseudoleptodus'
- 'Pseudoleptodus giganteus belongs to Pseudoleptodus'
- 'Pseudoleptodus grandis belongs to Pseudoleptodus'
- 'Pseudoleptodus granulosus belongs to Pseudoleptodus'
- 'Pseudoleptodus lepidus belongs to Pseudoleptodus'
- 'Pseudoleptodus nodosus belongs to Pseudoleptodus'
- 'Pseudoleptodus primitivus belongs to Pseudoleptodus'
- 'Roemerella gigantissima belongs to Roemerella'
- 'Sceletonia crassa belongs to Sceletonia'
- 'Schuchertella permiana is recombined as Goniarina permiana'
- 'Schuchertella subvexa belongs to Schuchertella'
- 'Streptorhynchus gregarium belongs to Streptorhynchus' according to Girty 1909
- 'Streptorhynchus gregarium is recombined as Tropidelasma gregarium'
- 'Streptorhynchus lamellatum is recombined as Diplanus lamellatus'
- 'Streptorhynchus occidentalis belongs to Streptorhynchus' according to Newberry 1861
- 'Streptorhynchus occidentalis is recombined as Meekella occidentalis'
- 'Streptorhynchus perattenuatum belongs to Streptorhynchus' according to Girty 1909
- 'Streptorhynchus perattenuatum is recombined as Tropidelasma perattenuatum'
- 'Streptorhynchus pygmaeum belongs to Streptorhynchus' according to Girty 1909
- 'Streptorhynchus pygmaeum is recombined as Tropidelasma pygmaeum'
- 'Streptorhynchus pyramidale is replaced by Chelononia straminea'
- 'Streptorhynchus pyramidalis belongs to Streptorhynchus' according to Newberry 1861
- 'Streptorhynchus pyramidalis is a subjective synonym of Meekella occidentalis'
- 'Streptorhynchus undulatum belongs to Streptorhynchus' according to King 1931
- 'Streptorhynchus undulatum is recombined as Tropidelasma undulatum'
- 'Tropidelasma anthicum belongs to Tropidelasma'
- 'Tropidelasma corniculum belongs to Tropidelasma'
- 'Tropidelasma costellatum belongs to Tropidelasma'
- 'Tropidelasma culmenatum belongs to Tropidelasma'
- 'Tropidelasma curtum belongs to Tropidelasma'
- 'Tropidelasma furcillatum belongs to Tropidelasma'
- 'Tropidelasma rhamphodes belongs to Tropidelasma'
- 'Tropidelasma robertsi belongs to Tropidelasma'
- 'Tropidelasma strobilum belongs to Tropidelasma'