4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 72 



2. Fusion of the nasal shield with the first supralabial or their 

 separation by a suture. 



3. Presence or absence of one or more scales between the nasal and 

 the shield bordering the pit anteriorly. 



4. The size and arrangement of the gular scales whether in regular 

 pairs bordering the mental groove or as less differentiated and irregu- 

 larly placed scales. 



It should be noted that the following discussion is based chiefly 

 on Siamese, East China, and Formosan specimens as there are no 

 specimens from India proper and the Himalayan region in the 

 United States National Museum. The few records I have from that 

 region I owe to the kindness of Dr. H. W. Parker, who kindly 

 examined a number of specimens in the British Museum, which are 

 of special interest in the present case. An examination of a much 

 greater material is necessary to settle the status of the western forms. 



1. SIZE OF INTERNASALS AND THEIR CONTACT OR SEPARATION BY 

 INTERVENING SCALES 



The internasals, or, as they are also often called, the supranasals, 

 vary considerably in size. When relatively large they are usually 

 broadly in contact along the median line ; when small they are widely 

 separated by several minute scales. 



All the specimens from Formosa and Eastern China from Chekiang 

 north and in the mountains farther south of which I have records — 

 17 altogether — have the internasals thus separated, the usual number 

 (in 11 specimens) being 2, exceptionally 1, 3, 4, or even 5. Four 

 specimens from central Yunnan show the same condition, 2 in three 

 cases, 3 in one. All the specimens from the Himalayan region which 

 Doctor Parker examined for me (11) except one also have the 

 supranasals separated by one (7) or two (3) scales. In one speci- 

 men from Darjeeling, which also differs in other respects from the 

 other five from the same locality, the supranasals are in contact. 

 In one from the Tack Plateau, Tenasserim, and another from, the 

 Lao Mountains, Cochin- China, they are also separated by one scale. 

 Therefore in 33 specimens out of 34 from the north an|d from the 

 higher mountain regions the supranasals are separated by one or 

 more scales. 



Of southern and lowland specimens I have examined a fine series 

 of 22 specimens from Siam collected by Dr. W. L. Abbott and Dr. 

 H. M. Smith; one from Cambodia, one from southern Fukien, one 

 from Tenasserim, and one from Java. In addition Doctor Parker 

 has furnished me data pertaining to two specimens from China 

 (cotypes of T. albolahris) ^ two from Hong Kong and one from the 

 Langbian Plateau, Annam, all in the British Museum ; altogether 31 



