1880.] MR. o'SHAUGHNESSY ON A NEW UBOMASTIX. 445 



5. Description of a new Species of Uromastix. By A. W. E. 

 O^Shaughnessy, Assistant in the Natural-History De- 

 partments of the British Museum. 



[Eeceived May 18, 1880.] 



(Plate XLIII.) 



Among some Lizards transmitted by Dr. Kirk from Zanzibar is a 

 very remarkable new species of the genus Vromastix, the type speci- 

 men of which is now in the British-Museum collection. The peculiar 

 shape of the tail and the extreme development of the upper caudal 

 scutes distinguish it immediately from the other species at present 

 known, five in number, viz. TJ. ornatus, Riipp., spinipes, Merr., acan- 

 thinvrus, JieW, fasciahis, Menetr., and microlepis, Blanf. I proceed 

 to give the following description of this well-marked sixth species. 



Uromastix princeps, sp. n. (Plate XLIII.) 



Head short and broad, covered above with numerous small irre- 

 gular-shaped scales, much as in U. acanthinurus and other species ; 

 the scales on the muzzle and the two central series between the 

 supraorbital I'egions are, however, larger, and there are two large plates, 

 a polygonal posterior and a narrow oblique anterior one, between the 

 nasal plate and the upper anteiior part of the orbital region on each 

 side ; also a series ot very large infraorbital plates ; the posterior 

 upper labials but slightly enlarged or projecting downwards. Ros- 

 tral broad, double the size of the mental — the rest of the scales of 

 the head offering no points of difference from JJ. acanthinurus or 

 TJ. microlepis, excepting that those on the temporal region are flat 

 and smooth instead of being convex. Sides of the neck with some 

 puckers, but without any larger pointed scales or tubercles. Neck, 

 back, and sides covered uniformly with very small, convex, rounded or 

 feebly pointed scales ; the scales on the lower surface of the body 

 are much larger, rhouiboidal, and arranged in transverse series. 

 Scales on the fore limb large, smooth, becoming still larger near the 

 carpal region ; no tubercular scales. On the upper and anterior part of 

 the thigh the scales are large, smooth and regular, not spinose, a few 

 large conical scales occurring behind and continuing at the knee and 

 down the front of the tarsus, the inner surface of which is covered 

 with rather large plain scales, similar to but larger than those of 

 the foot ; the other parts of the hind limb are covered with very 

 small scales. No femoral or praeanal pores in the specimen examined. 



The tail is broad, flattened, and much shorter than in the other 

 species of Uromastix, resembling in shape the tail of the genus of 

 Skinks named Silubosaurus by Gray. Its upper surface is covered 

 with very large spinose shields, projecting in a long curved point ia 

 the four middle shields of each of the 10 or 11 transverse rows, aud 

 forming a still larger series of more strongly curved or hooked ap- 

 pendages on each side of the tail ; thus there are six longitudinal 



