Isotely and Coralsnakes. 7 



black rings are divided by narrow red; or the whole snake is black 

 with narrow red rings. The frequent occurrence in Tropidodipsas 

 dumerili and T. fasciafa of red enclaves or vestiges within now black 

 broad bands which are separated by red narrow rings, shows clearly 

 what has taken place. The change from red, through orange into 

 red is so common an event in animals and plants that it needs no 

 further comment. 



2a 



2b 



3a 



3b 



Diagrams No. I. 



Evolution of the melanistic series with mostly double black rings. 



Fig. 1, 2a and '2b are represented by Coronella doliata, ct. p. 5 and 20. 



Fig. 2b and 3b, cf. p. 8. Au example of 3b is figured by Guenther, in: Biolog. Ceutr. 



Americ, Coronella micropholis, Tehuantepec, var. C. 

 Fig. 4. The typical condition; for examples see Fig. 5 of the table ou page 15. 

 Fig. 5. Various results and stages of the conversion of red into black bands; see 



p. 6, and Figs. 6—9 of the table ou page 15 ; also Plate I. 



An important side - departure takes place when the original 

 ocellar patches are so large as to become confluent, the peripheral 

 black curves touching each other first on the back, producing a 

 black inverted ä, the shanks of which alone enclose the yellow 



