160 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 46. 



specimens normally have three postoculars, whereas those from the 

 mainland as a rule have two. The island examples normally have 

 7 supralabials, and where they vary it is in the direction of an 

 mcreased number, or 8. Those from the mainland normally have 7 

 also, but when they vary it is in the direction of a reduced number, 

 or 6. 



The nearest ally of this serpent is Natrix sauteri (Boulenger), from 

 Formosa. There are no records of either from the intervening Riu 

 Kiu Islands. 



The material upon which this study was based consists of 20 

 specimens in the United States National Museum, 8 in the British 

 Museum of Natural History, 12 in the California Academy of 

 Sciences, and 6 records from hterature. 



