REPTlLIA 167 



rodent destroyer, though it does some damage to poultry and wild 

 birds. 



The Four-banded Coluber, Banded or Yellow Chicken Snake. C. 

 obsoletus quadrimttatus. This snake is found in the states from North 

 Carolina south, and west to the Mississippi. It is sometimes found on 

 the rafters of barns and chicken houses where it feeds not only upon rats 

 and mice but also upon eggs and young chickens. Whether the harm it 

 does in destroying poultry is more than balanced by the good it does 

 in destroying rodents is hard to determine. 



The Bull Snakes. Genus Pituophis, Fig. 109. The three species 

 of this genus, found in various parts of the country, are useful since 

 they feed largely upon destructive mammals. 



The Green Snakes. Cyclophis astivus and Liopeltis vernalis. These 

 small snakes are easily recognized by their uniform green color 

 above; the former, the Keel-scaled Green Snake, is the larger, has 

 keeled scales, as the name indicates, and is yellowish beneath; the 

 latter, the Green or Grass Snake, is whitish beneath, has smooth scales, 

 and is rarely over 20 inches long. They are very gentle snakes and 

 are useful as destroyers of insects. 



The King Snakes. Genus Ophibolus. This group includes some of 

 our well-known snakes, harmless to man, but often destructive to 

 venomous and other snakes; hence their popular name. They are 

 useful to man not only as destroyers of dangerous serpents but as 

 destroyers of mammalian pests. 



But two representatives of this group can be mentioned here; the 

 Common King Snake, Chain Snake, or Thunder Snake, O. getulus, 

 and the Milk or House Snake or Spotted Adder, O. doliatus triangulus. 



The Common King Snake, Fig. no, is a variable species that is 

 found generally over the United States south of latitude 40. It may 

 reach a length of 5 feet or more, and is usually black or dark, with 

 narrow whitish or yellowish lines across the back in a pattern some- 

 what like the links of a chain, hence one of its popular names. This 

 snake, so gentle toward man, not only destroys other snakes, but seems 

 quite immune to the venom of the deadly serpents. 



The Milk Snake is also variable and widely distributed, and is named 

 from the supposed habit it has of sucking milk from cows; this snake 

 does not steal milk, but is quite useful as a destroyer of rodents, espe- 



