The very young of the typical form, as well as that of the var. _viridiflavus_, has a striking livery (Plate IV., first figure), the head and nape black with yellow markings, or olive with black-edged yellow markings, contrasting sharply with the pale olive-grey of the body; the most conspicuous and constant of the yellow markings consist of a bar between the eyes, interrupted on the frontal shield, but sometimes continuous with the yellow of the postoculars, five or six small round spots on the parietal shields, and a V- or W-shaped line just behind the parietals, followed by one or two others separating the dark cross-bars which may be present on the nape, and occasionally even continue some way down the anterior part of the body. This livery persists in some half-grown specimens. In young individuals from Syria (var. _asianus_) the head is not differently coloured from the olive-brown body, and the markings described above appear as mere traces; on the other hand, the whole body has black and yellow spots or cross-bars above, and the belly is profusely marked with round black spots. In the new-born of the var. _caspius_, of which I have examined only one specimen, 11 inches long, from the Crimea, the head is olive-brown like the body, which bears dark brown spots and narrow cross-bars; and there is a dark brown streak along the middle of the nape, as is sometimes the case in the typical form. The belly is unspotted. A young from Malta is intermediate in its markings between the typical form and this variety. The young of the so-called black variety are not black at birth, but similar to the normal young of the races to which they belong. The four principal forms--_viridiflavus_, _gemonensis_, _caspius_, and _asianus_--are so completely connected that I cannot regard them as more than geographical races or varieties. _Size._--This handsome snake grows to a length of 6 feet, the var. _caspius_ even to 8 feet. I have seen a specimen of this variety, from Salonica, which measures 7-2/3 feet. _Distribution._--From the Atlantic coast of Europe to South-Western Asia. The typical form, in its narrowest sense, inhabits the Southern Tyrol, the north-eastern corner of Italy, and the countries to the east of the Adriatic, as far as Greece and Crete. The specimens from France, Switzerland, Italy, Giglio, Montecristo, Elba, Corsica, Sardinia, Sicily, and Malta, are mostly referable to the form known as _Z. viridiflavus_. Farther to the east the species is represented by the vars. _caspius_ and _asianus_, of which the distribution has been mentioned above. From Spain, this snake is only on record from Catalonia, not far from the French frontier.