28 



haying the fourth digit of each foot longer than the third, so it 

 cannot possibly fall under that division of the genus with the 

 occipital not enlarged, in which the third digit is longer than the 

 fourth. On the other hand, the Agama sinaita, Heyden, has the 

 third digit on both fore and hind limbs longer than the fourth. 



It seems probable that plate 5. figs. 3 and 4, viz. Merrem's 

 A. mutabilis, may be the lizard described by Eeuss, from Upper 

 Egypt, under the name of A. inermis, which, I believe, is the 

 species Mr. Blanford ' had in view as the one to which he also 

 would restrict the use of Merrem's name mutabilis. 



I have examined the types of A. sinaita, Heyden, and A. are- 

 naria, Heyden, preserved in the Frankfort Museum. The type 

 of the former is a male with no gular pouch, and with six large 

 prseanal pores, i. e. with the same number as occurs in the spe- 

 cimens in the British Museum referred to A. arenaria. The 

 dorsal scales are small and imbricate, but feebly so, of -^qvj uni- 

 form size but very regularly decreasing in dimensions towards 

 the sides, where they are very small, yet still feebly imbricate. 

 They are quite smooth on the anterior part of the body, but the 

 scales on the limbs and sacral region appear to have been keeled, 

 but only feebly so. The features of this individual are the small 

 size of the dorsal scales, the regularity of their arrangement, their 

 little imbrication, and their generally hexagonal form. The 

 scales on the ventral surfece are almost as large as the central 

 line of scales on the back, and are smooth, or feebly keeled, here 

 and there. The scales on the outsides of the limbs are con- 

 siderably larger than any of those on the body, are strongly 

 imbricate, and markedly keeled. The limbs are long and slender, 

 and the third digit of both limbs is the longest. The scales on 

 the top of the head are large, juxtaposed, and smooth, and there 

 is a spine at the posterior margin of the ear. The nostrU is 

 placed slightly above the canthus rostralis, and looks upwards 

 and backwards. The naked ear is larger than the eye-opening. 

 The tail is laterally compressed, and the scales are strongly 

 keeled. The coloration is completely faded. Sabitat : Arabia 

 Petrsea. 



A. arenaria, Heyden, is represented in the Frankfort Museum 

 by the two types from Upper Egypt presented by Eiippell. 

 They do not appear to me to differ from A. sinaita, except in 



1 Eastern Persia, ii. Zool. & Geol. 1876, p. 316. 



