It constitutes one of the numerous interesting novelties obtained by Mr. Darwin in the Galapagos. The specimens, which are of various ages, were taken in Chatham Island and in Charles Island.

Genus—CENTRURA. Bell.

Caput breve, triangulare. Aures magnæ, anticè cutis plicâ, haud dentatâ, partìm celatæ. Nares magnæ, rotundæ. Gulâ transversè subplicata. Collum atque corpus haud cristata; hoc depressum, latum, cute longitudinalitèr plicatâ. Cauda teres, basin versus subdepressa, squamis fortibus spinosis verticillatis. Squamæ capitis numerosæ, parvæ, rotundatæ, non imbricatæ—corporis minimæ, rotundæ, subconvexæ, læves. Pori femorales et præ-anales nulli. Dentes palatini.

The propinquity of this genus both to Oplura and to Doryphorus is very obvious. It differs, however, from both in several structural characters. From the former in the absence of denticulations on the anterior margin of the ear, and of a nuchal crest; from the latter in the presence of palatine teeth. Its place is probably between these two genera.

Centrura Flagellifer. Mihi.

Description.—Head almost equilaterally triangular, the muzzle rounded; scales of the head small, nearly equal, rounded, not imbricated, those of the temples subconical; nostrils round, large, confined to the nasal scales. Ears rather large, the tympanum lying beneath the surface, and partly concealed by an anterior fold of skin, which is not denticulated, as in Oplura. Skin of the neck folded at the sides, that of the body flaccid, and with strongly marked lateral folds, extending from the shoulder to the thigh. Scales of the neck and back very small, round, slightly convex, very smooth. Skin of the throat rugose, with a transverse pectoral fold not very strongly marked. Scales of the throat similar to those of the back; those of the belly broader and less convex; all perfectly smooth. Tail about the length of the head and body, flattened at the base, then round, surrounded with strong spinous verticillated scales, of which there are about fifty circles; beneath smooth. Legs of moderate length, strong, covered with small conical, imbricated scales. The toes compressed towards the extremity, and terminated with a strong, short, compressed nail.

Colour.—The colour can only be partially described, as the specimen has been long in spirits. It is of a dark brown colour above, with darker, obscure markings on the body. About the head are traces of green. The tail and limbs are rich brown, and the under parts dull, pale fuscous.

Familia—GECKOTIDÆ. Gray.
Geckotiens ou Ascalabotes. Bibr.
Genus—Gymnodactylus. Spix.
Gymnodactylus Gaudichaudii. Bibr.

Squamâ mentali impari pentagonâ, scutiformi; squamarum labialium inferiorum paribus quinque, superiorum paribus sex; caudâ medio crassiore.

This species was first brought from Coquimbo by Gaudichaud, after whom it was named by Mons. Bibron, who described it in his work; but as one specimen alone exists in the French National Collection, and as the species has never been figured, it is thought desirable that a figure should be given in the present work. The characters above given sufficiently distinguish it from all other species; but for a detailed description, the reader is referred to the “Histoire des Reptiles” above quoted.