118 
HORN EXPEDITION—REPTILIA. 
(iv.) The number of labials is by no means constant, but varies in the 
same individual on the two sides, and above and below on the 
same side. In our table N. Icevis of the Macleay Museum 
agrees very closely with the type N. platyunis. Specimen (^^) 
agrees more nearly with the type N. Iccvis in the number of 
labials, while it approaches N. platyiirus in the relative lengths 
of head, tail and fore-limb. 
(v.) The transverse grooves are conspicuous only in the specimen of 
N. Icevis in the Macleay Museum, and in (<;). These are both 
quite young individuals. 
Colour .—Upper surfaces soft rusty-brown or greyish-brown, with darker 
brown areas and pinkish-white cross bands, best defined on the occipito-scapular 
region and on the sacrum ; crown of the head darker than ground colour; a 
pinkish-white baud across the occiput, a second curved one on the nape, and a 
third, more angular, over the shoulders; a dark triangular band behind the 
occiput, a second crescentic dark band between the second and third light bands, 
and a third behind the third light band; two very broad dark brown cross bands 
on the sacrum, separated by a narrow pinkish-white cross band, the latter some¬ 
times assuming a T shape; usually about four faint curved light bands on the 
back ; all the light bands bearing rows of white tubercles; border of the eye and 
a spot in front of and one below the same white; a brown horizontal streak below 
and another vertical streak in front of the white spot before the eye; upper 
surface of tail darker, with rows of white tubercles. Under surfaces uniformly 
tender pinkish-white. 
It will be seen from the above facts that all the characters which have been 
relied upon to distinguish Pi. platyurus from Pi. Icevis., singly or collectively, fail to 
establish the distinction. 
Habits .—Found under logs and stones. 
Localities .—Charlotte Waters, Alice Springs, Tempe Downs, Illamurta. 
Distribution .—This species is met with freely in Central Australia. We have 
seen several specimens in addition to those collected by this Expedition Thargo- 
mindah, Queensland (De Vis.), Victoria Springs, and between Everard and Fraser 
Ranges (Elder Exped., 1892). 
