126 THE EEPTILES OF EGYPT. 
UROMASTIX. 
Uromastix, Merrem, Tent. Syst. Amph. 1820, p. 56. 
Body depressed, no dorsal or nuchal crest, covered with granular or small smooth 
scales, smaller than the ventrals, largest on the head ; head short, triangular, canthus 
rostralis obtuse, the nostril near the end of the snout ; tympanum naked, vertically 
elongate ; loose folds of skin on the neck ; a gular fold ; no gular pouch. Tail broad, 
depressed, strongly segmented, each segment consisting of quadrangular, strong, 
spiuose scales, in contact on the upper surface with the neighbouring segments, or 
separated from them on the upper surface by minute scales. Limbs short and stout, 
with strong claws ; hind limb with spinose tubercles. Praeanal and femoral pores. 
No canines ; the incisor teeth disappear with age, their place being taken in the 
upper jaw by a beak-like growth of the premaxillaries, covered with enamel. The 
anterior molars also disappear above and below, and the jaw becomes a sharp cutting- 
edge immediately behind the premaxillary beak. 
The term " Dabb," C^j, is applied by the Arabs to the species of this genus. 
The African species of Uromastix belong to that section of the genus in which the 
segments on the upper surface of the tail are not separated from each other by interposed 
small scales. The species are U. ocellatus, Licht., U. omatus, Heyden, U. agyptius, 
Hasselq. & Linn., and U. acanthinurus, Bell. 
There are two subdivisions of this section, viz. one in which the tail is encircled by 
the segments, which are as long on the under as on the upper surface ; and another in 
which this is not the case, as two or more transverse rows of scales on the under 
surface correspond to one of the dorsal segments. XI. ocellatus, Licht., and U. omatus, 
Heyden, belong to the first of these subdivisions, and U. cegyptius, Hasselq. & Linn., and 
U. acanthinurus, Bell, to the second. An Asiatic species, U. microlepis, Blanford, also 
belongs to this subdivision. 
The other primary section of the genus, in which the spinose segments on the upper 
surface of the tail are separated from each other by interposed small scales, is represented 
by three species, U. hardwicMi, Gray, U. asmussii, Strauch, and U. loricatus, Blanf., 
confined to Asia. 
