1912] 



Ditmars: Feeding Habits of Serpents 



215 



typical, non-venomous snakes. The relationship of our first group 

 of genera represented by species under observation/ may be simply 

 expressed as follows: 



Eutaenin 



Seminatrix 



Tropidoclonium 

 Clonophis 

 Storeria 

 Haldea 



All of the species are viviparous, and subsist altogether upon 

 cold-blooded prey. With the exception of Storeria and Haldea, the 

 members of these genera are semi-aquatic, although some of the 

 species of Eutaenia seldom enter water. However, Eutaenia and 

 Tropidonotus are closely related, the former possibly an immediate 

 off-shoot of the latter. Hence comparison is of interest. 



While the species of Tropidonotus quite persistently confine their 

 feeding to amphibians (batrachians), fishes, crustaceans, in fact 

 the creatures of the river banks and marshy places, we note a vari- 

 ance in the diet of those species of Eutaenia that have become quite 

 terrestrial and hence removed from a feeding ground generously 

 supplied with amphibians and fishes. These have the habit of prey- 

 ing upon earthworms. The writer has failed to induce any of the 

 North American species of Tropidonotus to take such food, nor will 

 the semi-aquatic species of Eutaenia, like E. saurita, sackeni, proxima 

 or radix eat earthworms. The upland forms of Eutaenia, however, 

 such as E. butleri, E. sirtalis and E. elegans will feed voraciously 

 upon them. There is no individuality among specimens to be noted 

 here. The variance of habits in Eutaenia, as stated, relates strictly 

 to the respective species involved, and is evidently a necessarily 

 acquired trait in a change from the ancestral lurking places. 



Feeding generally upon frogs, toads, salamanders and fishes, the 

 species of Eutaenia cannot be rated as of economic value. Their 

 depredations among frogs and toads, particularly the latter would, 



