HERPETOLOGY OF JAPAN. 285 



fused with seventh supralabial ; eight supralabials, fourth and fifth 

 entering eye, sixth and seventh largest; five lower labials in contact 

 with anterior chin-shields which are shorter than the posterior; 19 

 rows of scales, with two apical pits, all keeled; 170 ventrals; anal 

 divided; (tail broken). Color (in alcohol) pale clay-color, with 

 long, dark, dorso-lateral, slightly alternating blotches anteriorly 

 separated by whitish, black-edged, vertical bars on the sides, this 

 pattern shortening up posteriorly and resolving itself into smaller 

 dusky spots on the back and a series of whitish spots on the 

 sides; supralabials whitish, the anterior five with black posterior 

 margin ; an oblique black line from the middle postocular, across lower 

 portion of lower anterior temporal, sending a short branch downward 

 along upper third of posterior edge of sixth supralabial, crossing the 

 seventh labial nearly diagonally and the lower anterior corner of the 

 eighth labial to the angle of the mouth; the lower, anterior and upper 

 margins of the latter black, isolating a sharply-defined whitish spot; 

 behind the angle of the mouth a round whitish black-edged spot 

 continued backward and upward to the middle of the neck as a 

 similarly edged but slightly narrower whitish band forming a crescent, 

 or rather a chevron, on the nape; underside uniform pale, with a 

 series of small dusky spots on each side near the outer angle of the 

 ventrals and subcaudals. 



Dimensions. 



mm. 



Snout to vent 675 



Tail defective. 



The tail in this species is nearly one-third the total length. A 

 specimen in British Museum measuring 930 mm. has a tail 300 mm. 

 long. A similar proportion would give a total length for the specimen 

 described above of about 1 meter, probably near the maximum 

 length of this species. 



Variation. — Scale formula fairly constant. Temporals are said 

 rarely to be 1 + 2 ; the specimen described above has 2 + 1 instead of 

 2+2; it has also four postoculars on one side instead of three, the 

 normal number. Dr. Wall has recorded a specimen with two post- 

 oculars on one side. Ventrals range between 170 and 181 in thirteen 

 specimens, and subcaudals between 114 and 128 in seven specimens. 



Remarks. — The color pattern of head and nape of this species is 

 an enlarged copy of that of Natrix vahakari, craspedogaster, and 

 Ichasiensis: the black margin to the anterior supralabials; the oblique, 

 black postocular band crossing the upper half of the penultimate 

 labial and the lower margin of the last one, thereby separating it from 

 the others; the dark upper edge to the last thus isolating a well 

 circumscribed whitish spot on the latter; the subsequent postoral 

 light spot and temporo-nuchal crescent edged with dusky; each one 



