Boulenger, "A Synopsis of the Tadpoles of the European Batrachians," P.Z.S., 1891, p. 593; F.
Flower, "Batrachians of the Malay Peninsula and Siam," P.Z.S., 1899, p. 885; H.
Ferguson, "Travancore Batrachians," J.
The batrachians include a very large number of genera and species, especially in the Amazon valley.
1 The anatomical error in reference to the auricles of Reptiles and Batrachians on the part of Linnaeus is extremely interesting, since it shows to what an extent the most patent facts may escape the observation of even the greatest observers, and what an amount of repeated dissection and unprejudiced attention has been necessary before the structure of the commonest animals has become known.
The Reptilia include II species of the crocodile, alligator and lizard, including the savage jacare of the Amazon, several species of turtle, 4 species of batrachians, and 29 species of serpents, including the striped rattlesnake (Crotalus durissus), Lachesis mutus, and a rather rare species of Cophias.
Birds and mammals take the first place; the leading collections devote a good deal of attention to reptiles and batrachians; fishes and aquatic invertebrata are most often to be found only when there are special aquaria, whilst non-aquatic invertebrates are seldom to be seen and at most consist of a few moths and butterflies, spiders, scorpions and centipedes, molluscs and crustaceans.
Cold-blooded animals, such as reptiles and batrachians, thrive best in an equable temperature, and, especially in the case of snakes, frequently can be induced to feed only when their temperature has been raised to a certain point.
In zoology the siren (Siren lacertina), or "mud-eel" of the Americans, one of the perennibranchiate tailed batrachians, is the type of the family Sirenidae, chiefly distinguished from the Proteidae by the structure of the jaws, which, instead of being beset with small teeth, are covered by a horny sheath like a beak; there are, however, rasp-like teeth on the palate, and a few on the inner side of the lower jaw, inserted on the splenial bone.
He has observed that in young specimens of Siren lacertina (the larva is still unknown) the gills are rudimentary and functionless, and that it is only in large adult specimens that they are fully developed in structure and function; he therefore concludes that the sirens are the descendants of a terrestrial type of batrachians, which passed through a metamorphosis like the other members of their class, but that more recently they have adopted a permanently aquatic life, and have resumed their branchiae by reversion.
Among batrachians the parasites have been found, up till now, only in frogs; and among reptiles their occurrence has only been observed in one or two solitary instances (T.
Alytes obstetricans is of special interest as the first known example of paternal solicitude in Batrachians, and although many no less wonderful cases of nursing instinct have since been revealed to us, it remains the only one among European forms.
Boulenger, Tailless Batrachians of Europe (Ray Society, 1897).
He succeeded Haiiy as professor of mineralogy in the Museum of Natural History; but he did not confine himself to mineralogy, for it is to him that we owe the division of Reptiles into the four orders of Saurians, Batrachians, Chelonians and Ophidians.
Or Axolotl of Mexico were brought to him by Humboldt in the beginning of the 10th century, that these Batrachians were not really related to the Perennibranchiates, such as Siren and Proteus, with which he was well acquainted, but represented the larval form of some air-breathing salamander.
Reptiles and batrachians are abundant, but have been little studied.
Three coecilians, three batrachians (including a mountain-frequenting frog) and three fresh-water crustaceans are also indigenous, and about twenty-six species of land shells.
They are separated from fishes and batrachians (Pisces and Batrachians) on the one hand, and agree with reptiles, and birds (Reptilia and A y es) on the other, in the possession during intra-uterine life of the membranous vascular structures respectively known as the amnion and the allantois, and likewise in the absence at this or any other period of external gills.