1G4 Dr. A. GUnther on a new Genus of West African Snakes, 



some which would probably have occun-ed in his work. So 

 far as omitting all mention of the Collection of the British 

 Museum, Prof. Jan has only kept his word; and it being 

 allowed to everybody to leave his work as incomplete as he 

 pleases, I have no right to interfere with Prof. Jan's proceedings 

 on this point. It is another thing, however, with his method of 

 treating the genus Elaps. Being informed by me, during his 

 sojourn at the British Museum, that I had written a paper on 

 Elaps, he expressed himself anxious (in a letter directed to me) 

 to receive a copy of it. The publication of this paper (read be- 

 fore the Zoological Society, January 1859) being delayed by the 

 previously intervening vacation of the Society and the execution 

 of the accompanying plates, I communicated to him the distri- 

 bution of the genus which I had proposed, together with the 

 diagnoses and names of the genera. Now Prof. Jan may have 

 previously arrived at the same results, but he has substituted 

 new names, viz. Helminthoelaps for Callophis {Elaps remains 

 Elaps), Homoroselaps for Pcecilophis, Homaloselaps for Vermi- 

 cella. Such a multiplication of synonyms is the less justi6able 

 as the name of Callophis has been applied to East Indian Elaps 

 since the year 1832, and as there exists a second name for it, 

 Doliophis*. The denomination of Vermicella was introduced 

 into the literature early in 1858. 



So far on this point : on a second, I am happy to say, my 

 remarks are directed against a principle in herpetology which 

 appears to have found a rather strong representative in Prof. 

 Jan. He says of the South American Elaps, " Les especes 

 off rent dans leur ensemble, et dans la forme et la position des 

 plaques ce'phaliques, une telle ressemblance entre elles, qu'il est 

 difficile, pour la plupart, de les distinguer autrement que par 

 les dessins qui resultent de la distribution de leurs differentes 

 couleurs, ordinairement au nombre de trois — le noir, le rouge, 

 et le jaune. Ces dessins sunt assez constants dans les individus de 

 la meme espece." That is, as I understand it, " the coloration 

 becomes very constant as soon as you establish for every modi- 

 fication of colour a new species." Certain as it is that there 

 are different species of South American Elaps, it is equally so 

 that they vary indefinitely in coloration. It is impossible for 

 men who make their observations from preserved specimens to 

 decide in every case where is the boundary between variety and 

 species : this will be possible for those only who observe them 

 on their own native ground, and who are better informed as to 

 their localities than we are at present. On the other hand, we 

 know that there are some species of snakes which show an extra- 

 ordinary tendency to variation in what I call the ornamental 

 * Girard in Proc. Acad. Nat. Sc. Philad. 1857, p. 182. 



