Lacerta. 335 



Mahitat. — From West Africa (Liberia, Gold Coast, Cameroon, 

 Spanish Guinea, and Mouth of the Loango) to the Ituri (L. langi, 

 Schmidt) . 



This species occupies an isolated position. Were it not for the 

 more primitive condition of the ventral plates, it might be thought to 

 be derived from the L. muralis group, especially as it shows points of 

 agreement with L. jaeksonii in the strongly depressed head, the dorsal 

 scales, and the absence of the parietal foramen ; it also agrees with it 

 in having a single postfrontal bone. The occasional absence of the 

 interparietal shield, in connexion with the loss of the parietal 

 foramen, is an anfomaly more frequent still in Philochortus spinalis. 



Section VI. Thetia, Gray. — Ventral plates not overlapping, the 

 transverse series with rectilinear border, in 10 or 12 longitudinal 

 series ; two superposed postnasals ; lower eyelid with a transparent 

 disc. Pterygoids toothless. 



A single species. 



29. LACEETA PEESPICILLATA. 



Lacerta perspicillata, Dum. & Bibr. Erp. Gen. v, p. 249 (1839) 

 Guichen. Explor. Sc. Alg., Eept. p. 12, pi. i, fig. 3 (1850) ; Strauch, 

 Erp. Alg. p. 34 (1862) ; Bedriaga, Abh. Senck. Ges. xiv, 1886, p. 29-5 ; 

 Bouleng. Cat. Liz. iii, p. 43 (1887), and Tr. Zool. Soc. xiii, 1891, 

 p. 126; Anders. Proc. Zool. Soc. 1892, p. 13; Doumergue, Erp. Oran. 

 p. 127, pi. viii, figs. 9, 10 (1901) ; Chabanaud, Bull. Mus. Paris, 1916, 

 p. 231. 



Thetia perspieillata, Gray, Cat. Liz. p. 32 (1845). 



Body depressed. Head rather strongly depressed, If to If times as 

 long as broad, its depth equal to the distance between the centre or the 

 posterior border of the eye and the tympanum, its length 3^ to 4 times 

 in length to vent in males, 4 to 5 times in females ; snout pointed, a 

 little shorter than the postocular part of the head. Pilaus 2 to 2i 

 times as long as broad. Neck as broad as the head or a little broader. 

 The hind limb reaches the shoulder or a little beyond in males, the 

 wrist, the elbow, or the axil in females ; foot as long as or a little 

 longer than head ; digits slender, compressed. Tail cylindrical. If to 

 If times as long as head and body. 



Nostril separated from the labial and the postnasals by a narrow 

 rim, also from the rostral ; nasals forming a short suture ; fronto- 

 nasal usually broader than long,* much broader than the internarial 

 * Sometimes in contact with the frontal, according to Doumergue. 



