20 



GUIDE TO REPTILES AND AMPHIBIANS. 



(241) of this species distinguished by the absence of black patches 

 at the back of the head. The other harmless British species is the 

 Smooth Snake {Corojiella ausirinca, 261), found in England only 

 in the south, and there but seldom. Both these Snakes have large, 

 shield-like scales on the top of the head, and thereby differ from the 

 Viper, as shown in the accompanying cuts. Other well-known 

 Snakes of the group are the North American Water-Mocassin 

 {Tropidonotus fasciatus, 242), the Indian Rat-Snake {Zamenis 

 mvcosus) and the American Black Snake {Z. constrictor, 250), and, 

 belonging to another genu.s, the European Four-lined Snake 

 {Coltil)er quatuor-lineatus, 253), the North American Bull-Snake {C. 

 melanoleucus), and the South American Bushmaster {C. corais, 255)- 

 The Australian DendropTiis punctidatus (257) is a good example of 

 the Tree-Snakes, while the Small-scaled Snake {Coronella microphoUs, 

 262), with its alternate l)ands of black and scarlet, displays a type of 

 colouring very uncommon among Serpents. 



An extremely interesting Snake in this family is the African 



Fig. 18. 



African Egg-eating Snake {Dasypdtis scabra) ; ^ nat. size. (No. 272-) 



Egg-eating Snake {DasypeUis scahr/i, 272, fig- l-*^), which typifies a 

 sub-family {DmypeUiiue) by itself. Its gi-eatest peculiarity is that the 



