98 PROCEEDINGS OF THE NATIONAL MUSEUM vol.66 



peh specimens: 21 sec; 141-145 v.; 35-39 siibc. ; 7 lab. It is along 

 the northern boundary between A. hrevicaudus and A. intermedius 

 that we expect and, indeed, find intermediate specimens. Thus Mr. 

 Sowerby collected two specimens (Nos. 52339 and 52341) in southern 

 Manchuria on the Yalu river, the boundary against Korea, about 180 

 miles from its mouth. Both have 21 scale rows and 7 labials, negative 

 characters but in case of doubt pointing towards A. hrevicaudus 

 rather than A. intermedius; one has 143 ventrals and 41 subcaudals, 

 well within the limits of A. hrevicaudus. But the other one, which 

 it would be absurd to refer to under a different sub-specific name, has 

 151 ventrals and 44 subcaudals. On page 452 of the Herpetology of 

 Japan I said that " it would be impossible to say to which of the 

 three forms {hrevicaudus or the two forms of intermedius) a speci- 

 men with 151 ventrals and 45 subcaudals were to be referred unless 

 it had 8 supralabials in which case it should probably be referred to 

 intermedius. In the present instance, however, I have no hesitation 

 in calling it A. hrevicaudus^ the decisive factor of course being the 

 fact that its companion is typical of this form. Were it not for these 

 dubious intermediate specimens in the geographically intermediate 

 territory we would be justified in applying a binominal appellation 

 rather than the present trinominal. 



AGKISTRODON STRAUCHI Bedriaga 



1912. Ancistrodon strauchi Bedriaga, Wiss. Res. Przewalski Central-Asien 

 Reis., Zool., vol. 3, sect. 1, pt. 4, June 1912, p. 728, pi. 10, figs. 1-ld 

 (type locality, Tungolo and Tatsienlu, Szechwan, Cliiua ; cotypes, Petro- 

 grad Mus. Nos. 8533-8534; Potanin, collector). 



1912. Agkistrodon tibetanus Bakbour, Mem. Mus. Comp. Zool., vol. 40, 

 No. 4, August, 1912, p. 133, pi. 2, figs. 3^ (type locality, Ramala Pass 

 beyond Tatsienlu, western Szechwan, 13,000 feet ; type, Mus. Comp. 

 Zool., no. 7327; W. R. Zappey, collector). 



Of this recently described remarkable species, as yet very rare 

 in collections, Mr. Graham has sent three fine si^ecimens collected 

 in July, 1923, at Ngan Yang, western Szechwan, at an altitude be- 

 tween 13,000 and 14,000 feet. This locality is evidently not far 

 from the type localities of A. strauchi and A. tihetanus. Ap- 

 parently the species is of very restricted distribution and is possibly 

 limited to the high plateau of eastern Tibet above 13,000 feet 

 altitude. 





