198 NOTES ON TWO SPECIMENS OF SPITTING-SNAKES PEOM SOUTHERN RHODESIA 



Spitting-Snakes' 



Sib, — The correspondence which has iippcared in the last unnibers of the Field confirms a fact which has 

 been known for a long time to travellers in tropical and South Africa. Whenever the spitting-snake has been 

 scientifically determined it has proved to belong to the genus Naia (cobras) or to its near ally Sepcdon, of which 

 a single species, S. hannachates, the ring-hals of Cape Colony, is known. 



But only certain species of cobras appear to be endowed with this curious habit. It has never been observed 

 in the Indian cobra, Naia Iripudiaiis, the type species of the genus, although an Eastern form, inhabiting 

 Southern China and the Malay Peninsula and Archipelago, has received, probably not without reason, the name 

 of Xaia SfiiUatrix. In Africa we have six species of Xaia : 



1. JV. haic, inhabiting the countries bordering the Sahara, and extcndiug, though rare, to East Africa as far 

 south as the Transvaal. It occurs also in Palestine and in Arabia. 



'2. A', flnva, from Cape Colony. 



3. y. iticlanolciica, from West Africa (Cruiuea to Angola), and Central Africa, eastwards to Uganda. 



4. A', nicjricollis, from the whole of tropical Africa, from Senegambia and Nubia, to Angola and the 

 Transvaal; occurring also in Ai'abia. 



5. X. ancfiieke, from Angola and Ovambolaud. 



U. y. goldii, from the Lower Niger and Cameroon. 



The two latter are rare, and no observations have been made on them in the live state. 



yaia haic, the common cobra of Egypt, has never Ijeeu observed to spit poison. Hy. S., cpiotiug 

 Sir Andrew Smith, gives X. haic as the scientific name of the South African spitting-suake, but Sir Andrew Smith 

 was mistaken in his identification, and the snake he had in view is N. /lava, a quite distinct species. 



As Xaia mclnnoleiica and N. nit/ ricol lift occur together in most parts of Africa where the spitting has been 

 witnessed, and as both are regarded by the natives as "spitters," it is not possible to decide at present whether 

 they agree in this respect, IJut, so far as my own information goes, the habit has been authentically established in 

 the latter only. The snakes brought houu; by Mr. Lort Phillips and Dr. Donaldson Smith, as having spat at 

 them, belong to X. niijricollis. Professor Barboza du Bocage, the veteran Portuguese zoologist, tells us in his 

 Hci-pibiloijic d'Anijnla (p. 13.3) that a cmpiimirn (spitting-snake) sent to him from Angola, and which he kept 

 alive for several months, during which it often displayed its power of e.iecting poison at a considerable distance, 

 was a X. nujriculliis. Dr. A. Bavay, in the Bulletin of the French Zoological Society for 1895, has published some 

 interesting observations on the " Serpent Cracheur de la Cote occidentale d'Afriquc," without, however, having 

 been able to settle the question of the species. 



He is inclined to refer the snake to X. hair, but the description applies better to X. iiinrirollix, which is 

 common in Dahomey, where the observations were made by JI. Lc Naour. In his recently published Ijook, 

 f.ra Vciiins, Dr. Calmette suggests that the Dahomey snake may have been a Scpcjlon hcviiuichalct:, overlooking, 

 however, the fact that that snake is not known to occur in West Africa. Dr. Calmette rightly objects to the 

 habit being ascrilicd to X. haic, of which he has kept numerous specimens in his laboratory without ever 

 witnessing any attempt on their part to shoot out poison. I think it is now well established that X. haic, is not 

 endowed with this faculty any more than the common X. Iripitdians of India. That closely related species should 

 behave so differently is very remarkable, and this again shows how important it is to correctly determine the 

 species, or to i:)reserve specimens for future identification, when making oljscrvatious on the habits of animals. 



For the present, therefore, only three species are known, on trustworthy authority, to sjiit poison. These are : 

 ^cpcdoii h.rKmachates, Xaia flnva, and Xaia uiiiricullis ; to those X. iiiclanolcuca must probably be added. 



It would be interesting to make further observations on this subject with due reference to the species, tlic 

 correct identification of which may be facilitated by the following synopsis: Scpcdoii is at once separated from 

 the cobras proper by its keeled dorsal scales, which, as in our common viper or adder, bear a raised ridge aloug the 

 middle. The cobras, Xa.ia, have smooth scales. X. haic and X. aiichir/a: differ from the other sjiecies in having 

 a series of small shields separating the eye from the large shields bordering the upper lip. The former has a 

 large hood (the inflatable neck) with twenty-one or twenty-three scales across it, and there are nineteen or 

 twenty-one scales in a series across the body, whilst in the latter the neck is scarcely dilatable and bears seventeen 

 rows of scales like the body. In the other species one or two of the largo shields of the upper lip border the eye ; 

 in X. flami, X. mclanolcuca, and X. goldii the sixth or the seventh of those shields is the largest in vertical 

 diameter, whilst in X. niyricollis the third is the deepest. In X. flava the rostral shield (capping the end of the 

 snout and bordering the mouth) is as deep as broad, and there are tweutv-three scales across the neck : in 

 X. luclaiwleuca the rostral shield is considerably broader than deep, and the scales across the neck number 

 twenty-three to twenty-nine. In X. goldii the rostral shield is broader than deep, the scales across the neck 

 number only fifteen, and the eye is much larger thau in the other cobras, its diameter being two-thirds its 

 distance from the end of the snout. Attention to these few points should enable anyone to correctly name a dead 

 cobra, even a dry skiu ; and the value of future observations on habits would be greatly enhanced by such a 

 discrimination. 



U. A. BOULESGEU. 



There is a noteworthy divergence of views expressed in the following letter, appearing 

 in the Field of April 18, 1908. So far as I am aware, no reply was published : — 



Spitting- Snakes 



Sir, — In an article on this subject in your issue of Feb. 1, Mr. Boulenger states that the spitting habit 

 in snakes, on scientific investigation, has only been proved to belong to the South African ringhals (Scpcdon 

 hoimacJuites) and certain African species of cobra (Xaia). He further remarks that it has never been observed 



> From the Field, February 1, 1908 



