52 HYDB0PH1S NIGEOCINCTA. 



two post-oculars ; three temporal shields on the side of each occipital. 

 Two pairs of chin-shields, the anterior of which are in contact with each 

 other. Twenty-seven to twenty-nine series of scales round the neck. 

 Scales imbricate, rhombic, keeled ; those on the highest side of the body 

 as broad as long. Ventrals distinct, not quite twice as broad as the 

 scales of the adjoining series ; smooth ; 320-331 in number. Four large 

 anal-shields. The tail terminates in a large scale. The trunk is 

 encircled by 43(53-)-61 complete rings of black colour. The width of 

 these rings is equal on the sides and on the belly ; on the vertebral 

 line only they are a little broader ; they are narrower than the inter- 

 spaces, which occupy from four to five transverse series of scales, whilst 

 a black ring occupies only three. The interspaces are greenish-olive on 

 the back, yellowish on the sides and on the belly. The crown of the 

 head and the upper lip are blackish, a yellow band running along the 

 whole upper margin of the head ; lower jaw whitish. Tail with from 

 nine to eleven black cross-bars." 



