ACANTHODACTYLUS BOSKIANUS. 149 
from the labial margin by the fourth and fifth, and occasionally by the fifth and sixth 
labials. Ear denticulated in a varying degree. Temporal scales more or less elongate, 
in some examples obtusely keeled, in others smooth and conical. Dorsal scales small 
from the occiput to the shoulder, rhomboidal, imbricate, carinate, increasing in size at 
the shoulder, very much larger on the hinder part of the back, where they pass into the 
large scales on the base of the tail ; 8 to 16 rows between the thighs. Thirty-five to 58 1 
rows of scales round the middle of the body ; ten rows of ventral plates, exceptionally 
twelve, broader than long, and in longitudinal and transverse series. Usually a prseanal 
plate with two or three smaller plates anterior to it, and also laterally, but sometimes 
all are more or less broken up. Limbs well developed, variable, the hind limb may 
reach as far as the eye or only to the shoulder. Digits on the fore and hind limbs 
covered with three rows of plates, viz. a dorsal, ventral, and externo-lateral, the latter 
forming a denticulated border stronger in some than in others, but always more 
developed on the outer edge of the toes, but shorter than their diameter. Tail 
generally more than twice the length of the body and head, covered above with strongly 
keeled scales, those on its under surface, at the base, being smooth or feebly keeled. 
The femoral pores vary from 15 to 32. 
The young has generally six narrow, white, longitudinal lines along the back and 
sides, arising from behind the ear and occiput, and separated from each other by five 
broad blackish bands ; another similarly coloured band nms along the lower border of 
each of the outermost white bands. The black bands are generally more or less spotted 
with white, and are prolonged on to the tail. Occasionally a seventh white band is 
present along the mesial line of the back. The upper surface of the head is uniform 
brownish or even bluish grey, the sides being more or less spotted with brown. Under- 
pays white. Three longitudinal lines or bands may persist in a varying degree into 
the adult stage, but generally they become obscure and the dark bands are broken up 
into longitudinal lines, or areas of alternate black and white or somewhat rufous or 
grey spots, the white lines being only feebly indicated. In many the bands and lineation 
all but disappear. Tail of half-grown specimens generally coral-red in its latter two- 
thirds. 
The largest male I have met with in Egypt (Abukir) measures 79 millim. from the 
snout to the vent, and the tail 163 millim. ; but it attains to a greater size, for the 
corresponding measurements of an individual of the same sex from the Hadramut are 
86 millim. and 190 millim. respectively. 
This species is common along the margin of the desert among stones and loose soil 
and sparse vegetation, and also on the embankments of canals and roadways. It is 
very plentiful along the banks of the Freshwater Canal at Suez, which are fringed in 
many places with long grass growing in the water, and amid the stems of which the 
lizard runs for shelter when pursued, clinging on to them in the water. It is also 
1 Lataste counted 52 rows of scales round the middle of the body. 
