_Coloration._--Young (Plate VI., top) with three or five alternating longitudinal series of dark brown, black-edged spots on a yellowish, grey, or pale brown ground, the spots of the median series largest, transversely elliptical or rhomboidal; a dark streak across the forehead, black bars on the labial shields, and a black oblique streak from the eye to the angle of the mouth. In specimens from Italy and the countries bordering the Adriatic (the typical _C. quatuorlineatus_) the markings very gradually disappear with age, with the exception of the temporal streak, whilst a pair of black streaks appear along each side of the body, at a short distance from the head, the lower corresponding to the postocular streak, the adult being brown without spots, but four-lined (Plate VI., second figure). In more eastern specimens (_C. sauromates_, Pallas), which may be regarded as representing the original form, the markings of the young persist throughout life, or, if they disappear, they are not replaced by dark streaks (Plate VI., third figure). Lower parts pale yellow, closely spotted or marbled with brown, these markings usually disappearing in the adult, except on the tail. Iris dark brown. _Size._--The largest European snake, stated to reach a length of 8 feet. The largest specimen examined by me measures, however, only 4-1/2 feet. _Distribution._--Aldrovandi's Snake inhabits Southern Italy and Sicily, Istria, Croatia, Dalmatia, Herzegovina, Greece, and eastwards to Southern Russia, Transcaucasia, Asia Minor, and Persia. It has been observed at an altitude of 2,600 feet in Herzegovina. All the specimens from Roumania, Bulgaria, Turkey, and eastwards, belong to the var. _sauromates_, which is regarded by some authors as worthy of specific rank. The reported occurrence of _C. quatuorlineatus_ in various parts of France is certainly due to confusion with _C. scalaris_ and _C. longissimus_. _Habits._--Dry as well as marshy localities are the abode of this large and handsome snake, which often approaches the dwellings of man, attracted by the poultry. Comparatively slow in its movements, it is more easily captured than any of the other large Colubrids of Europe, and does well in captivity, where it should be provided with a tank, in which it will remain for hours under water. It is as good at swimming as at climbing. Biting readily when captured, it becomes of gentle disposition after a short period of captivity. In consequence of its slow, phlegmatic temperament, it often allows itself to be picked up when surprised in liberty, but as soon as it feels the grasp it turns round and defends itself. It appears to feed exclusively on mammals and birds, up to the size of a rat or dove, and will readily take dead food. It has a predilection for eggs, and has often been observed to swallow hens' eggs.