HERPETOLOGY OF JAPAN. 



317 



In the young (No. 21193) (fig. 272) the markings are darker and 

 more distinct ; the pattern on the head shows a fleiir-de-hs figure on the 

 interparietal suture ; the hiteral dark spots on the underside are l:)lacker, 

 broader, with a convex anterior outline; there are three pale dorsal 

 Hues, the median one not well defined and interrupted by the dark 

 crossbars, the lateral ones on the fifth, sixth, and seventh scale rows 

 continuous and cutting ofi^ a series of blackish lateral spots from the 

 dorsal dark crossbars. 



This pattern is often retained in tolerably large specimens. 



Variation. — The variation in our Korean material is quite insig- 

 nificant; thus all possess a subpreocular, but, as might be expected 

 in a species of so wide distribution, many anomalies are found 

 when a large series is studied. Strauch examined 84 

 specimens from nearly the entire range, and has enu- 

 merated the deviations he found. Thus five specimens 

 lacked the subpreocular on both sides and five on one 

 side ; thirteen had three postoculars on both sides and 

 six had three on one side; four specimens had nine 

 supralabials on both sides and two specimens only seven 

 on both sides, wdiile eleven had nine or seven on one 

 side only. The number of scale rows varies in about 

 even proportions between 23 and 25 in 43 speci- 

 mens." As to the subcaudals, Strauch mentions as a 

 curious anomaly only found in some east Siberian and 

 west Chinese specimens that some of the subcaudals 

 are entire. 



The number of ventrals varies betw^een 172 and 214. 

 In this a slight tendency to geographical variation can 

 be traced. Thus in 42 specimens from Siberia the 

 ventrals vary between 180 and 214 in those west of the Yenisei River, 

 but between 172 and 195 in those from east of that river. In 17 

 Chinese specimens they vary again between 180 and 213 ventrals, 

 while in five Korean specimens the number is 203-207. 



One of our specimens (No. 21190) shows the anomaly of having on 

 both sides a small shield cut off from the third supralabial between it 

 and the loreal. Another (No. 1433 1 ) has two presuboculars on each side. 



Ilahitat. — A species of extraordinarily wide distribution, ranging, 

 as it does, from the valley of the Volga in southeastern Russia through 



Fig. 272.— Elaphe 

 dione. 2 x nat. 

 SIZE. Top of 

 HEAD. No. 21193, 

 U.S.N.M. 



a Curiously enough, in 21 specimens in British Museiim enumerated by Boulenger, 

 of which 12 were from China, from which country Strauch had no specimens, 13 have 

 25 scale rows, 6 have 27, and only 2 have 23. All our Korean specimens have 25, and 

 I am inclined to regard this as the normal numlier. This agrees with Doctor Wall, who 

 found 23 in 3, 25 in 10, and 27 in 1 Chinese specimens, and with Doctor Werner, who 

 in 4 specimens from China found 3 with 25 and 1 with 27 scale rows, the latter in a spec- 

 imen from Tsingtau. 



