(From our own Correspondent.)IN Wiedersheim's recently published book, “Salamandrina perspicillata und Geotriton fuscus,” two very little-known tailed amphibians (Urodela) are described and compared anatomically, which, by their entire organisation, stand at the two opposite limits of the Salamandrinæ that are known to us, representing the highest and the lowest form of these. Salamandrina perspicillata, which is rather a land than a water animal, seems to be found only in the western half of Italy; it is a prettily coloured, small, and slender animal, which lives on insects, and during the dry summer months continues in a kind of summer sleep, but in winter it is found in full vital activity. In its skull are almost entirely wanting the cartilaginous parts denoted as the “primordial cranium,” so that in this it rises above all other Salamandrinæ, and comes near the Reptiles. In accordance with this, also, is the existence of a cavity in the base of the skull (sella turcica), the prolongation of the frontal bone (frontale) into the eye cavity, and a roofing-over of the latter; lastly, the absence of a special nose-partition (which, again, quite characterises the Reptiles). On account also of the course of development of its vertebræ, and the numerous bones of its carpus and tarsus, Salamandrina perspicillata must stand at the top of the Salamandrinæ its divided kidneys, again, suggest the reptile, so that we must look on this animal as a form rendering possible the transition from the Amphibia to the Reptilia, and which, on account of its peculiarities, might represent a separate family. Geotriton fuscus, on the other hand, holds quite a different position. If, in view of the numerous anatomical relations adduced, we are able, commencing with Salamandrina perspicillata, and passing through the various water salamanders (Tritons), to the land salamander (Salamandra maculata), to form a descending series of ever less-developed forms, Geotriton fuscus comes at the lower end of the series, for in many respects it ranks with the lowest Amphibia generally, the Perennibranchiata. Indications of this appear in the fewness of bones in the skull and the tarsus, the extended double cone form of the soft-cartilaged vertebrae; then, too, the joint processes are wanting, &c. On the other hand, Geotriton is distinguished in the most peculiar way, by one organ, from all other Amphibia, viz., by the tongue. This is a pedicelled disc, like a mushroom, on the bottom of the mouth cavity, where it is connected with the tongue-bone apparatus; the latter, however, does not merely consist of the same parts as in other Amphibia, but at its two hinder ends there is attached, on either side a long thin cartilage, which reaches, free between the neck muscles and the skin, as far as the back, and is enclosed in an envelope of special muscles, which are only attached at its hinder end and in front to the rest of the tongue-bone. If, now, this muscle be contracted, it thrusts out the cartilage rod, and with it the tongue, in a way similar to that observed in Chameleons, Woodpeckers, and Ant-eaters. Compare the annexed drawing. Thus Nature connects in the most remarkable manner a complicated organ of the higher Vertebrates with the organisation of amphibians that evidently stand very low.