110 HELICOPS ERYTHROGRAMMUS. 



one nearly six, while the Tropidonotus bipunctatus (sirtalis) never reaches four 

 feet in length. The two animals also differ entirely in colour, and this is even 

 uncommonly well marked in Daudin's plate. The one has the body dusky, with 

 pale yellow longitudinal lines; the other is bluish-black, with longitudinal lines of 

 red, so remarkable as to afford a specific character;* an arrangement which never 

 occurs in any serpent of this country, and as far as my observations have 

 extended, never in any other. 



Schlegel further believes that the Helicops erythrogrammus is a variety of the 

 Homalopsis (Helicops) plicatilis, the result of climate, to which I can by no 

 means consent, as they differ greatly in several particulars. The Helicops 

 plicatilis is reddish-brown above, more or less shaded; the Helicops erythro- 

 grammus is deep bluish-black, with three bright red longitudinal lines; the former 

 has a single anterior frontal plate, the latter has two; the one inhabits South 

 America, and the other is found only in the United States. 



* Serpent a raies rouges. 



