HERPETOLOGY OF JAPAN. 429 



diytauce from rostral, but shorter than that from tip of snout, shghtly 

 brdader than supraocuhirs ; parietals longer than frontal, the inter- 

 parietal suture equaling the distance of frontal from rostral; no 

 loreal; one preocular; eye small, not larger than preocular; two 

 postoculars; two anterior obli({ue temporals, the lower one being the 

 upper cut-off portion of fifth (sixth on right side) supralabial; 7 

 supralabials on left side, 8 on right, second 

 largest, fifth, sixth, and seventh (sixth, sev- 

 enth, and eighth on right side), very low, 

 subequal, third and fourth (third and fifth 

 on right side, the interpolated fourth not 

 reaching the orbit) entering eye; 3 lower kig.Soi.-disteira cyanocincta. 

 labials in contact with anterior chin-shields ijxtimesnat. size, side view 



1 . 1 ] .1 , • ■ 4^^ ^ 4-4. „ • OF HEAD. No. 33931, U.S. N.M. 



which equal the posterior pair, the latter m 



contact throughout; 33 rows of scales on neck, 41 on middle of body, 

 the latter with a bituberculate keel; 329 ventrals which are nearly 

 smooth; four elongate, subequal anals; 38 subcaudals; tip of tail 

 with a slightly enlarged scale. Color (in alcohol) pale yellowish, 

 back suffused with gray, the skin between scales black ; 53 dark gray 

 crossbands, broadest and darkest, nearly black, on back, 5 on tail; 

 top of head olive gray fading into a paler tint on labials and throat. 



Dimensions. 



Head small, neck fully as wide, Ijody very elongate, its greatest height not far 



from the vent, posteriorly considerably compressed. 



Ill III . 



Total length 1. 290 



Snout to vent 1, 180 



Vent to tip of tail 110 



Width of head 14 



Diameter of neck 15 



Greatest height of body 46 



Greatest heigh t of tail . 24 



The male is less elevated behind and the scales and ventrals strongly 

 tuberculate. 



Variation. — Of the head shields probably the supralabials are sub- 

 ject to the greatest variation, 7 being the normal, while the eighth may 

 be interpolated at various points and thus make the formula appear 

 more unstable than it really is. The arrangement of the anterior 

 temporals is characteristic ; the difference from that of D. Tnelanocepliala 

 was pointed out under the latter species. The coloration is rather 

 variable inasmuch as occasionally specimens have been found having 

 the upper surface uniformly dark without cross-bands or rings, while 

 on the other hand individuals having a black longitudinal band along 

 the underside uniting the dark rings are common. 



Habitat. — This is one of the most widely distributed and commonest 

 of the sea snakes, extending as it does from the mouth of the Euphrates 



