Thick-tailed Gecko, Underwoodisaurus milii and Marble Gecko, Underwoodisaurus milii, Christinus marmoratus

Plate 132, Figure 1. The Thick-tailed Gecko, Phyllurus miliusii (now known as the Thick-tailed Gecko, Underwoodisaurus milii)

Plate 132, Figure 2. The Marbled Gecko, Diplodactylus marmoratus (now known as the Marbled Gecko, Christinus marmoratus) found in Echuca

Figure 1

The Geckoes form one of the most peculiar divisions of the saurian reptiles. They are all small disagreeable-looking Lizards inhabiting warm countries, and are nocturnal in their habits, catching insects, especially caterpillars and other larvæ, and worms, on which they feed by night; and hiding under the bark of trees and in other crevices by day, and especially shunning the glare of the sun, in which the other kinds of Lizards delight.

The legs are strong, the feet short, with the toes rather short and nearly equal in length, usually furnished with sharp, retractile claws, like those of a cat, for climbing the bark of trees, and generally furnished with transverse membranous plates below, recalling the structure of the foot of a fly, and enabling them to run up smooth surfaces, such as a perpendicular wall of a house, or on the ceiling of a room, with great swiftness, darting on the flies and other insects, which it can only catch with its jaws, by pouncing on them and swallowing them whole, the oesophagus or gullet being unusually large, to allow of this more of feeding, and the articulation of the lower jaw being far behind the head, as in the crocodiles, to form a large gape.

Like most nocturnal animals, the eyes are very large, and the pupil usually vertical and elliptical, with fringed edge; the eye-lids are continuous, like those of the chameleon, the under one very small, and the upper very large; and a transverse winking one moving transversely between them.

They are remarkable for uttering a sharp, loud cry or click, in some species like the word "Geck-o," from which their name arises.

The skin seems soft and almost naked, from the minuteness and granular character of the scales, the head being destitute of conspicuous plates, unlike most Lizards. The tail is less than the body in length, and so brittle that it falls off even from a slight jar or sudden awkward movement from fright; the new tail, which soon replaces the lost one, is generally slightly different in size, color, and scaling from the original, and must not be mistaken for a new specific character; it is generally depressed, often fusiform, and sometimes flattened and dilated.

The males are smaller, more slender, and more agile, and more brightly colored than the females.

The brown and grey mottled colors of most of the species vary a good deal at will, to assimilate to the tint and style of coloring of the bark, &c., on which they rest, and from which only the brilliancy of their eyes distinguishes them. Their movements are sudden, and surprisingly swift and noiseless.

The present species, P. Miliusii, is one of the most striking Geckoes of the slender-toed group, having the toes bent nearly at right angles with each joint, giving them the appearance of having been broken or deformed. The broad, thick, heart-shaped tail, and beautiful, transverse, dark and light banding of the color of the upper surface, render this one of the most striking Lizards of the northern warm parts of the colony. It is rarely found south of Sandhurst.

Figure 2

Like all the Geckoes, these Diplodactyli are small, nocturnal Lizards, with the tips of the toes generally more or less dilated. This species is a good example of those having an apparent doubling of the greatly swollen distal ends of the toes, with the terminal joint and claw so minute as to seem hid in the notch between the two large pads.

They live on insects and worms, which they swallow whole, the oesophagus being very large. The males are smaller than the females. The tails are very brittle and easily list, reproduced with some slight differences, from the original in the form of the scales, &c.

The species is abundant in the northern parts of the colony, found lurking under the deciduous bark of trees in the day time, the brownish of purplish-ashy mottlings almost exactly coinciding in appearance with the bark, rendering them very difficult of detection except for the brightness of the beautiful bronze eye. Some specimens have the transverse, dark marbling more distinct, and with the light color less broken, while others have the pattern more complex. The under-side is destitute of markings in all the species. The specimen figured is from Echuca.

Not figured of the color of life before.