COLUBRINE GROUP. 207 



inhabiting Hungary and the Mediterranean countries, and extending as far north 

 as the south of Switzerland ; while in the east it is represented by a variety known 

 as the Balkan snake, which attains a larger size than the typical form. These 

 snakes are distinguished from their allies by the regular arrangement of the shields 

 on the head, and the presence of two preorbital shields, of which the lower is small 

 and placed in the line of the labials ; and they are further characterised by the 

 relative shortness of the tail, which scarcely reaches a fourth of the total length. 

 The smooth scales are arranged in from seventeen to nineteen rows. The ordinary 

 form may attain a length of about 4 feet, but is generally smaller. In ground- 

 colour the head and nape are greyish yellow, the back and tail greenish, and the 

 under-parts yellow, upon them being black markings, which, while irregular above, 

 form regular oblique bars inferiorly, and in the hinder part of the body are 

 arranged in longitudinal stripes which continue to the end of the tail. In some 

 specimens, however, the ground-colour of the upper-parts is a beautiful yellowish 

 green, while on the lower surface it is canary-yellow ; in a third variety the whole 

 upper surface is uniform olive-brown, and in some cases it is completely black, the 

 under surface of the body being grey, with a steely blue lustre on the sides and the 

 whole of the under-parts. This snake is very abundant in Italy, and may be met 

 with in most gardens in the neighbourhood of Rome. Its habits vary to a certain 

 extent according to locality; and while in the Russian steppes it frequents the 

 hottest and driest spots, in Dalmatia and the Tyrol it is found in sunny, although 

 by no means dry situations, either in woods or among old buildings. 



The other European species is the horseshoe snake (Z. hipno- 

 Horseshoe Snake. , . 



crepxs), common both to Southern Europe and Northern Africa, and 



represented in the lower figure of the illustration on p. 208. From its allies it 

 is distinguished by the presence of a series of small suborbital shields beneath 

 the eye, which completely separate it from the upper labials, by the divided 

 anal shields, the presence of from twenty-five to twenty-nine longitudinal rows of 

 scales on the body, and likewise by the constancy of the coloration. Measuring 

 nearly 6 feet in length, this handsome snake has the ground-colour of the upper- 

 parts varying from greenish or greyish yellow through orange to reddish brown. 

 As a rule, the head is marked by a dark oblique band between the eyes, behind 

 which is a second band, convex in front, and reaching to the neck, and a third 

 marked with light spots, so that a horseshoe pattern is formed between the spots 

 and bands. On the back runs a row of yellow-edged dark oval patches, which 

 tend to unite towards the hinder extremity ; and on each side of this are a series 

 of smaller spots, beneath which, again, are more upright dark marks, extending 

 downwards to the lower surface. As the upper dark patches are very large, the 

 ground-colour is generally reduced to a series of rings, forming a very regular and 

 pretty pattern. The under-parts are yellow or orange-red, spotted with black. 



Here also must be mentioned the Indian rat-snake (Z. rnucosus), 



Rat-Snake. . . . v ' 



now included m this genus, although formerly referred to the next. 



It is a large species, attaining a length of 6 feet or more. In colour it is brown 



above, frequently with more or less distinctly defined black crossbands on the 



hinder-part of the body and tail ; the under surface being yellowish, often with 



black edges to the shields of the hinder-part of the body and tail. The range of 



