PROTEUS ANGUINUS, a blind, newt-like perennibranchiate Amphibian, about a foot long, found in the Adelsberg, Maddalena, and other limestone caverns of Carinthia and Carniola. The creature is white or flesh-coloured, and the transparent gills appear blood red; the skin passes uninterruptedly over the rudimentary eyes. The animal’s body is cylindrical; the snout is long and blunt; the fore-feet have three toes, and the hind (which are set very far back) two. There are three gill-arches and two gill-slits on each side. The absence of the fourth branchial arch is a feature that Proleus has in common with Menobranchus and also with Spelerpes. The skull is of an elongated form, and presents several remarkable characters. The trabeculae cranii are persistent, as in the snake. The membrane bones are singularly few, the maxillae being rudimentary and the nasals and supraoccipital absent. In the lower jaw the splenial is said to be absent, but a mento-Meckelian cartilage element is present, as in Batrachia. The palatines have a row of teeth, and are ankylosed with the pterygoids; the premaxillae, dentaries, and vomers carry teeth. The absence of a cartilage roof to the nasal cavity is one of the many characters in which Proteus agrees with Menobranchus, but differs from Siren and Menopoma. The suspensorium has only a simple pedicle, as in Batrachia, and the hyoid arch is remarkable for the enormous hyo-mandibular element, which is larger even than in many sharks. The notochord is scarcely constricted by the amphicoelous vertebrae, and the intervertebral cartilages are at a minimum of development. There are twenty-nine trunk vertebrae, one sacral, and twenty-eight caudal. The pectoral arch contains a long thin ossified scapula, a suprascapula, and a long precoracoid separated by ...