HYOSTYLIC. AUTOSTYLIC. Subclass 1. ELASMOBRANCHII. Subclass 3. HOLOCEPHALI. 1. Ichthyotomi. 1. (unknown). 2. Selachii. 2. Chimaeroidei. 3. Acanthodii. 3. (unknown).
Subclass 2. TELEOSTOMI. Subclass 4. DIPNOI. 1. Crossopterygii (Palaeozoic 1. Sirenoidei. and Mesozoic). 2. Crossopterygii (Cainozoic). 2. (unknown). 3. Actinopterygii. 3. Arthrodira.
The primitive forms in each of these four subclasses have the fins archipterygia (see p. 127).
Family =Amphiumidae=. Megalobatrachus. Cryptobranchus (Menopoma). Amphiuma.
Family =Salamandridae=. Salamandra--salamander. Molge--newt. Onychodactylus. Amblystoma. (Siredon--axolotl, larval Amblystoma). Batrachoseps. Spelerpes (Gyrinophilus).
Group =Temnospondyli=. _Archegosaurus._ _Nyrania._ _Euchirosaurus._
Group =Stereospondyli=. _Capitosaurus._ _Mastodonsaurus._
Family =Caeciliidae=. Siphonops. Epicrium.
Family =Discoglossidae=. Discoglossus--painted frog. Bombinator--fire-bellied frog. Alytes--midwife frog.
Family =Pelobatidae=. Pelobates--toad frog.
Family =Bufonidae=. Bufo--toad. Docidophryne.
Family =Cystignathidae=. Ceratophrys--horned frog.
Family =Ranidae=. Rana--common and edible frogs.
Group =Anomodontia=. _Dicynodon._ _Udenodon._
Group =Pariasauria=. _Pariasaurus._ _Elginia._
Group =Theriodontia=. _Dimetrodon._ _Galesaurus._ _Cynognathus._
Family =Plesiosauridae=. _Plesiosaurus._ _Pliosaurus._
Family =Trionychidae=. Trionyx--snapping turtle.
Family =Dermochelydidae=. Dermochelys (Sphargis)--leathery turtle.
Family =Chelonidae=. Chelone--green turtle.
Family =Chelydridae=. Chelydra--terrapin.
Family =Ichthyosauridae=. _Ichthyosaurus._
Family =Sphenodontidae=. Sphenodon (Hatteria).
Family =Rhynchosauridae=. _Hyperodapedon._
Family =Proterosauridae=. _Proterosaurus._
Family =Pygopodidae=. Lialis--scale-foot.
Family =Agamidae=. Draco--flying lizard. Agama.
Family =Anguidae=. Ophisaurus (Bipes, Pseudopus). Anguis--blindworm.
Family =Amphisbaenidae=. Chirotes. Amphisbaena.
Family =Scincidae=. Tiliqua (Cyclodus). Scincus--skink. Chalcides (Seps).
Family =Typhlopidae=. Typhlops--blind snake.
Family =Colubridae=. Tropidonotus--ringed snake.
Family =Crotalidae=. Crotalus--rattlesnake.
Family =Atlantosauridae=. _Brontosaurus._
Family =Megalosauridae=. _Megalosaurus_ (_Ceratosaurus_).