6 PROCEEDINGS OF THE NATIONAL MUSEUM vol.72 



In the northern and highland series of 34 specimens (including 

 those from central Yunnan) such intercalated scales are present in 

 all except 1, namely, the same Darjeeling specimen in the British 

 Museum which has been shown above to be an exception in the two 

 previous characters. 



In the southern and lowland series of 32 specimens, scales are 

 present on both sides in only 8 specimens, while in 1 specimen, 

 from Cambodia, a small granule is present on one side. In 2 of the 

 8 the intercalation is only indicated by a minute granule on both 

 sides. 



Expressed in percentages Ave thus find that in 97 per cent of the 

 northern and highland form there is present one or two intercalated 

 scales between the two shields, while in the southern and lowland 

 form the two shields are adjacent the whole length without any inter- 

 calated scales or granules in 67 per cent of the series. 



Fig. 1. — Teimeiebsdeus gramineds geaminbuSj nat. size, a. Top op head ; 6. side op 

 head; c. underside op head. No. 70342, U.S.N.M. from Nong Mono, Keabin, Eastern 

 SiAMj collected bt Dr. Hugh M. Sjiith. 



4. SIZE AND ARRANGEMENT OF GULAR SCALES 



In these snakes we find only the anterior pair of chin shields 

 (genials) developed, while the posterior part of the mental groove 

 is bordered by smaller scales. In some cases these scales are of the 

 usual elongate shape of gulars, in others the scales forming the 

 border of the groove are more or less modified into larger, broader, 

 and more rounded scales arranged in more or less regular pairs. 

 The typical arrangement of these two styles is well shown in the 

 accompanying illustrations. (Figs. 1 and 2.) Most of the speci- 

 mens in the two forms agree plainly with one or the other of the 

 two styles thus figured. But there are many individuals in both 

 groups which show intermediate features. 



