314 BULLETIN 58. UNITED STATES NATIONAL MUSEUM. 



Dimensions. 



mm. 



Total length 1, 580 



Snout to vent 1, 330 



Vent to tip of tail 250 



The young have a very characteristic head pattern. Thus, in the 

 specimen in the Philadelphia Academy of Sciences (No. 15255), from 

 Seoul, Korea, the ground color is brownish with white black-edged 

 bands and spots, as follows: A broad band from upper postocular 

 over temporals past the last supralabial, confluent with the white 

 underside; a black line from lower postocular over suture between 

 seventh and eighth supralabials to edge of lip ; a w hite spot on frontal 

 anteriorly, and a small one on each of the parietals near the frontal; 

 an interrupted white cross band on supraoculars; a festooned white 

 band across anterior half of prefrontals; a white spot on rostral; a 

 white horizontal band from nostril to preocular; seinicircular black 

 markings on anterior supralabials ; an inverted Y-shaped white mark 

 on upper neck; back with rhomboidal brown black-edged spots sepa- 

 rated by whitish cross bands. 



Halfgrovm specimens, such as U.S.N.M. No. 21 189, show traces of 

 this pattern, especially on the posterior part of the body and on sides 

 of head ; this specimen also has indication of a checker pattern on the 

 underside. 



Very old specimens are often nearly uniform pale isabella-color. 



Variation. — Apparently the most variable feature of the scutella- 

 tion of this species is the frequent absence of the subpreocular. Thus, 

 out of 11 specimens Strauch found it lacking on both sides in five, 

 while of my five Korean examples it is absent in three on one side. 

 Only in one of our specimens is there a ninth supralabial on one side, 

 while in the Michigan University specimen from Korea the number of 

 supralabials is reduced to six on one side and seven on the other. The 

 number of scale rows appears to be very constant, all the 19 speci- 

 mens on record or examined by me having 23. The number of ven- 

 trals is also confined within narrow limits, namely, 208 to 226. The 

 subcaudals do not exceed 76 and rarel}^ go as low as 61. One speci- 

 men (U.S.N.M. No. 21186) has an undivided anal, and I also believe 

 that it is undivided in the young specimen in the Philadelphia 

 Academy of Sciences. 



Hahitat. — Eastern Asia from the River ^Vi-gun, the tributary of the 

 Amur, ranging east to the sea. The cotypes were collected in the 

 Khinggan Mountains by Doctor Radde, accordmg to Schrenck, but 

 as I can not find that Radde ever visited the main body of tliis chain, 

 which is situated in Chinese Manchuria, it is most likely that he ob- 

 tained his specimens along the borders of the rivers Argun and Amur, 

 which skirt the mountains mentioned. Dybow^ski collected it at 

 Vladivostok and Posiet Bay, near the Korean frontier, and m Korea 



