Merrem, 1820, "Tentamen systematis Amphibiorum."
Pholidota. [The Reptilia.]
Batrachia: APODA.
Batrachia: SALIENTIA.
Batrachia: GRADIENTIA { Mutabilia [with metamorphosis, e.g.
Batrachia: GRADIENTIA { Newts.]
Batrachia: GRADIENTIA { Amphipneusta [Perennibranchiate Urodeles.]
F. S. Leuckart, 1821, "Einiges ueber die fischartigen Amphibien."[[5]]
Monopnoa. [The Reptilia.]
Dipnoa. [The Amphibia] { with temporary gills: Ecaudata + Caudata pt.
Dipnoa. [The Amphibia] { with permanent gills: "Proteidae," Menopoma
Dipnoa. [The Amphibia] { and Amphiuma.
Latreille, 1825, "Familles naturelles du règne animal." The Vertebrata are divided into Haematherma and Haemacryma. These terms for warm and cold-blooded creatures were later on amended by Owen to Haematotherma and Haematocrya. The latter are divided by Latreille as follows:–
Reptilia. Still including the Coeciliae amongst the Snakes.
Amphibia { Caducibranchiata.
Amphibia { Perennibranchiata.
Pisces.