SNAKES 103 



nauseous excretion of the skin-glands at the back of 

 the neck, and may have been evolved independently 

 of mimicry altogether. Zaocys carinatus is in colouring 

 very like a Cobra, but I am not aware if it imitates its 

 attitude. Its near ally Zamenis mucosus is said by 

 Captain S. S. Flower 1 to rear up its head like the 

 Cobra and to dilate its neck ; this, however, is not 

 effected by lateral extension as in the Cobra, but by 

 the ventral shields, which are thrust out so far as to 

 become acutely keeled, the skin on the side of the 

 neck being widely stretched, and showing up the yellow 

 skin between the brown scales just as in the Cobra. The 

 resemblance between Coluber radiatus and the Cobra 

 has already been noted. The same authority states 

 that the similarity in colouring between the harmless 

 Lycodon subcinctus and the deadly Bungarus candidus 

 is very close, but it is to be noted also that though 

 the geographical ranges of these two species overlap 

 they do not coincide entirely, for the poisonous species 

 is unknown in Borneo, although the non-poisonous 

 one occurs there. Brilliant scarlet in combination 

 with other colours is, as we have seen, characteristic 

 of three of the Bornean poisonous snakes, and it has 

 often occurred to me that this scarlet colour when 

 appearing in other snakes may possibly be regarded 

 in these cases also either as warning colours adver- 

 tising distasteful properties, or as mimetic of warning 

 colours. For instance, one of the harmless Colubrines 

 Calamaria leucogaster [leucocephala 1 C. H.] has a red tail 

 and belly: again in Cylindrophis rufus the red on the 

 tail is conspicuously displayed when the animal is in 

 a posture of defence, whilst its near relation C. lineatus 

 ' P.Z.S., 1899, pp. 666-7. 



