38 



PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 77 



TRIMERESURUS GRAMINEUS GRAMINEUS (Shaw) 











Internasals £^^ 



First su- 



pralabial 



fused with 



nasal 



Nasal 

 separat- 

 ed from 

 . second 

 suprala- 

 bial 



U.S.N.M. 



















67517 (S739) 



Nontaburi 



Nov. 



13, 1923 



2 



2 + 5] 



pairs 



Yes 



Yes 



67518 (S936) 



Bangkok 



Mar. 



13, 1923 



2 



2 + 5 



11 



Yes 



Yes 



70285 (S1833) 



(( 



Mar. 



18, 1925 



2 



2 + 4 



(I 



Yes 



No 



70286 (S2086) 



(( 



Aug. 



23, 1925 



— 



2 + 5 



II 







70287 (S2110) 



(( 



Sept. 



22, 1925 



2 



2 + 4 



11 



Yes 



No 



70288 (S2118) 



(( 



Sept. 



27, 1925 



2 



2 + 4 



11 



Yes 



No 



70342 (S2192) 



Nong Mong 



Aug. 



26, 1925 



2 



2 + 4 



i( 



Yes 



No 



70347 (S1961) 



Pak Jong 



May 



18, 1925 



2 + 2" 



2 + 6 



H 



(15) 



No 



70350 18 



11 





(( 













70351 (S2011) 



Lam Tong 

 Lang 



July 



20, 1925 



2 



2 + 5 



11 



Yes 



No 



70352 (S2012) 



(( 





(( 



2 



2 + 5 



11 



(17) 



No 



70353 



(( 



July 



— , 1925 



2 



2 + 5 



11 



No 



Yes 



70354 



(( 





(( 



2+1 " 



2 + 6 



II 



(17) 



No 



72075 (S2764) 



Bangkok 



Aug. 



5, 1926 



2 + 1 1* 



2 + 5 



It 



Yes 



Yes 



72076 (S2779) 



({ 



Aug. 



16, 1926 



2 



2 + 5 



It 



Yes 



No 



72077 (S2899) 



(( 



Mar. 



31, 1926 



2 



2 + 4 



II 



Yes 



No 



75682 (S3492) 



(( 



Aug. 



4, 1927 



2+1 H 



2 + 5 



11 



Yes 



Yes 



76121 (S3934) 



(( 



July 



6, 1928 



2 



2 + 5 



II 



Yes 



Yes 



All the vipers have the two large internasal plates generally in con- 

 tact with each other, but occasionally separated by one or two small 

 scales. Following the two pairs of enlarged chin shields, there are 

 from four to six quite regular pairs of scales before the first gastro- 

 stege is reached. 



In all the Bangkok vipers, as well as in the one from Nontaburi, 

 the first supralabial is completely fused with the nasal in front of the 

 nostril. 



In the Lam Tong Lang specimens the first supralabial and the 

 nasal are entirely distinct in one case (70353); in two cases the fusion 

 is only partially completed as a trace of the original suture line is 

 still plainly evident (70352 and 70354); in one specimen the fusion 

 is complete (70351). In the snake from Pak Jong (70347) the fusion 

 is complete on the left side of the head, while the right side shows the 

 first supralabial and the nasal plate quite separate from each other. 



In 6 out of 18 snakes a small scale is present between the posterior 

 edge of the nasal plate and the second supralabial. The other 12 

 have the nasal and the second supralabial directly in contact. 



" Azygous. 



" No on right, yes on left. 



M Embryo of 70347. 



" Partially. 



