IOWA ACADEMY OP SCIENCE 151 



**Chrysemys picta (Hern) 



Clirysemys marginata (Agassiz) 



Chrj^semys belli (Gray) 



Cistudo ornata (Agassiz) 

 **Cistudo Carolina (L) 



With the hope that it may aid somewhat in the recognition of these 

 interesting animals, the following keys are offered for two of the most 

 readily recognized groups of this order. These keys have been adapted 

 from the works of Cope, Jordan, and others and are simply intended 

 to include the Iowa forms. The characters used in separation of species 

 have been chosen with the aim of making the keys of some use to the 

 student of little technical training rather than the specialist who will 

 have access to monographs covering the details of structures and treat- 

 ing in full of the hemipenial and osteological characters. 



The "Garter Snakes" (Eutaenia B. & G.) 



The genus Eutaenia B. & G. includes a number of rather small and 

 conspicuously banded snakes, which from their type of coloration, are 

 commonly called the "Garter Snakes" or the "Ribbon Snakes." The 

 genus includes our most common snakes and from the fact that the 

 species readily accomodate themselves to widely varying conditions of 

 habitat, some of them are to be found at any locality in the state. The 

 species are all valuable from an economic point of view and since all 

 are harmless they should be protected. One of the most absurd sights 

 I ever witnessed was in the park of a small city, where three men and 

 five small boys succeeded in killing a small "Garter Snake" while 

 several women stood around interestedly admiring the heros. In 

 using the following key, it should be noted that most of the species have 

 both light and dark forms and frequently intermediate forms appear 

 which makes the coloration a rather varying and uncertain character 

 for recognition of a species. 



EUTAENIA B. & G. 



Lateral stripe on third and fourth row of scales; scales in 19 rows. 

 Scales little or not at all spotted. 



Tail long (over one-third of total length); slender species. 



Chocolate brown with three bright yellow stripes; ventral plates 

 150 to 160. 



Sattrita B. & G. 



Tail shorter (from .25 to .3 of total length); relatively stout species. 

 Blackish, with dorsal stripe brownish yellow and lateral stripes 

 greenish. V. P. 165-170. 



Proxima B. & G. 



