20 Hans Gadow, 



black appears in rather broad rings. Against these 2 species stand 

 3 opisthoglyphous and 6 aglyphous genera with about 10 species, 

 and it is at least my own personal experience in Mexico, born out 

 by tbe numbers of specimens in good xlmerican and European 

 Museums, that the barmless kinds in Elapoid dress are much more 

 common than Elaps. Tbe supposed advantage of its dress witb 

 reference to other creatures must thereby be seriously impaired, 

 but it would be fuUy justified when referred to pbysiological, con- 

 stitutional, and environmental, physico-chemical agencies. 



The resemblances between Elaps and some other snake are 

 often surprisingly close, almost to minute detail in pattern and 

 colours. Sometimes these close resemblances occur in the same 

 district, more often not. The pattern which the otherwise most 

 versatile Coronella cannot produce is the very kind which is the 

 socalled typical dress of Elaps fulvius, and in which this likewise 

 most versatile snake appears invariably in Northern Mexico and in 

 the United States! Coronella has hit oif the wrong combination! 

 This being so, the cases of close resemblance in the same districts 

 are reduced to mere luck}- coincidences, the luck supposed to be on 

 the side of Coronella. 



Within the United States great resemblances to Elaps are 

 reduced to the genus Coronella, and from Florida to Lousiana with 

 the addition of the monotype Cemophora coccinea which is a Coronella 

 modified for digging. The genus Coronella {Opliibolus and Osceola 

 of American authors) flourishes much in North America, where it 

 has produced a great number of varieties, the synonymy of which 

 is in confusion. It suffices for our purpose that tliey show the 

 tendency of changing from North to South from a pattern more or 

 less brown with dark blotches or saddles, into one which is sharply 

 ringed, red with double black rings divided by yellow, typical 

 instances of series DM. This gradual progressive change is best 

 illustrated by the species which are commonest in the states East 

 of the Mississippi. 



Three of these Kingsnakes, called thus because they occasion- 

 ally eat poisonous kinds, for instance Elaps itself, are beautifully 

 figured in Ditmahs, Reptile-Book, New York, 1907, tab. 105. 



Opliibolus doliatus triangulus, New York State, Shades of olive- 

 brown; blotches complete, reaching but a moderate distance down 

 the sides; interstices pale. 



0. doliaius dericus, Maryland. Blotches complete, but reaching 



