60 LacertidcV. 



consideration the numerous exceptions whicli justify tlie course I have 

 followed. 



I am unable to express an opinion on the var. kurtuana, Kaschenko, 

 Ann. Mus. Zool. St. Pi'tersb., xiv, 1909, p. 125, from Central Asia. 

 Size small (85 millim. from snout to vent) ; tail sometimes nearly 

 twice as long as head and body ; masseteric plate much enlarged. 



I regard L. agUis, and more especially the vars. chersonensis and 

 ■ex!(jua, as the ancestral type from which L. viriilis on the one hand and 

 the species of the L. muralis group on the other have been evolved. 

 As regards the latter, the oriental species with two postnasals are con- 

 nected with it through L. jjarva. The other species, with primarily a 

 single postnasal, are separated by a wider gap, which is only partly 

 filled up by L. taurica and L. peloponnesiaca. If I am right, South- 

 ■eastern Europe and the neighbouring part of Asia are to be regarded 

 as the centre of origin of the genus Lacerta — a view which is confirmed 

 by the study of the L. viridis-oceUafa series. 



How the markings of the striated form of the L. muralis group can 

 be derived from the more primitive pattern of the young L. agilis, var. 

 •exigua is explained further on, when dealing with L. parva. 



2. LACERTA PARVA. 



Lacerta jxtrva, Bouleng. Cat. Liz. iii, p. 22, pi. i, fig. 1 (1887) ; 

 Werner, Sitzb. Ak. Wien, cxi, i, 1902, p. 1080, pi. i, fig. 4, and pi. ii ; 

 Steind. Ann. Hofmus. Wien, xx, 1905, p. 308 ; Nikolsky, Mitth. Kauk. 

 Mus. iv, 1909, p. 306 ; Nesterov, Ann. Mus. Zool. St. Petersb. xvii, 

 1912, p. 74 ; Nikolsky, Herp. Caucas. p. 90 (1913) ; Bouleng. Tr. 

 Zool. Soc. xxi, 1916, p.' 36, pi. ii, figs. 10-12. 



Head and body feebly depressed. Head small, If to If times as 

 long as broad, 4,V to 4^ times in length to vent in males, 4f to 5 times 

 in females, its depth equal to the distance between the anterior corner 

 of the eye and the tympanum ; snout obtusely pointed, as long as the 

 dista,nce between the eye and the tympanum, with feebly concave 

 loreal region ; cheeks not much swollen ; length of pileus twice its 

 width. Neck as broad as head, or slightly constricted. Limbs rather 

 short ; hind limb reaching the wrist, the elbow, or the axil in males, 

 limbs just meeting or hind limb reaching the wrist or the elbow in 

 females; foot longer than the head; digits feebly compi*essed. Tail 

 ■cylindrical, 1^ to If times as long as head and body. 



Nostril pierced between the nasal and two postnasals, usually also 

 the first upper labial. Nasals forming a short or very short suture; 



