ON COMMON INDIAN SNAKES. 101 



Freaks are apt to occur among all animals, but that rare condi- 

 tion known as axial bifureafion or ■ dichotomy, which gives rise to 

 dual heads developed forkwise on the same body has been recorded at 

 least three times in this species. I wrote* of one such specimen in this 

 Journal and two others are reported as being in the Indian Museum by 

 Sclaterf. Dentition. — The maxilla supports an anterior and a posterior 

 series of teeth. The anterior set number 5, the first 3 progressively 

 increasing in size t, the last 2 about twice the length of the 3rd. 

 An arched toothless gap intervenes between the anterior and 

 posterior sets. The posterior set numbers 10 or 12, the last 2 are 

 about twice the size of the preceding 8 or 10 which are subequal in 

 size. • 



The polato-pterygoid array form an uninterrupted series of which 

 the palatine numbering 11 to 13 are rather longer, the pterygoid 

 numbering as many as 29 progressively and very gradually diminish 

 in length from before backwards. 



In preparing a skull the minute teeth at the back are very difficult 

 to preserve and dissect out intact, so that usually a number consider- 

 ably less than 29 are evident. 



Mandibular. — Consist of two series, an anterior and a posterior, 

 separated by a short gap. The anterior contains 5 teeth, the 3 first 

 progressively increasing in length, the 4th and 5th equal and about 

 twice as long as the 3rd. The posterior set numbers from 16 to 20. 



These figures are given from an examination of 4 skulls lying 

 before me. 



Giinther's§ statement that "Each maxilla is armed with two fangs 

 in front, placed in a transverse line, the outer being much larger 

 than the inner" is incorrect. The two fang-like teeth are subequal, 

 and placed one behind the other. Similarly, the last two teeth in the 

 posterior maxillary set are enlarged, not only the last as stated by 

 him. Boulengerl says the maxillary teeth increase in size posteriorly 

 which seems to imply a gradual increase. This does not clearly 

 describe the condition. It is the last two teeth which are suddenly 

 and distinctly enlarged. 



* Vol. XVI. p. 387. 

 t List. Snakes, Ind. Mus., 1891, p. 14. 



t Only one is seen in my figure, the first two are not noticeable owing to the bending 

 icwr.rds of the mx\illa. 



§ Rept. Brit., Ind. 1864, p. 316. ^ Cat., Vol. 1, p. 348. 



