■300 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVII 



After death the hood is obliterated, and if the creature is stiff 

 cannot be readily demonstrated, and I have frequently under 

 these conditions known people express surprise when told that the 

 specimen is a cobra, shake their heads, and think they know better. 

 Again, I have seen the loose skin about the neck of a harmless snake 

 pulled out, and a hood claimed where none existed, so that one 

 must admit that in a few cases, at least, the cobra is not recognised, 

 and sometimes a harmless snake is mistaken for it. Nicholson's footnote 

 on page 159 of his work on Indian snakes is a striking corrobora- 

 tion of my own experience. He says : " I have seen an Englishman, 

 " considered rather an authority on snakes, declare that a Ptyas 

 " mucosus (now Zamenis mucosus) just brought to me was a cobra ; 

 "he even pointed out the poison-fangs." So long as people continue to 

 be guided by these' faulty characters in diagnosis, mistakes are sure 

 to occur. 



Now there are one or two very distinctive peculiarities about the 

 scales of a cobra which if looked for should place its identity beyond 

 question. These are as follows : — 



The prceocular shield touches the internasal (see Pra. and Int., Fig. 

 16 B). In only one other snake is this relationship to be found, viz., 

 in Xylophis perroteti, a small harmless snake peculiar to the hills 

 of Southern India. In this snake, though, the 3rd supralabial shield 

 does not touch the nasal.* 



Between the kth and 5th infralabial shields a smalt wedge-shaped scale 

 occurs, the " cuneate" (see Fig. 16 B). Sometimes a second or even a 

 third similar scale borders the lower lip. This scale may easily be over- 

 looked, lying partly or wholly concealed, as it may do, by the over- 

 lapping of the upper lip, so that the mouth should be opened when 

 looking for it. It occurs in no other land snake. I have never even 

 observed it in the hamadryad, but it is seen in a few species of sea- 

 snakes. A head is rarely so broken that one or other of these points 

 cannot be made out on one side. If, however, the head is mutilated 

 beyond recognition there is one feature about the scales over the back 

 of a cobra which is peculiar to itself. It is the concavity in the arms 



* This is a very easy point to determine if it is remembered that the shields immediately 

 behind the rostral (in land colubrines) are called internasals, and the shields touching the 

 eye in front the prieoculars. In the single instance, where the prefrontal shield touches the 

 eye as in Fig. 19, it is obvious that this shield from its size and position has a prior claim 

 to be considered a prefrontal, and in such a case the praocnlar is said to be absent. 



