132 Lacertidn'. 



but also iu the shape aud arraugemeut of the head-shields, especially 

 those surrouiidiug the nostril, aud the occasioual separation of the 

 fourth supraocular from the frontoparietal,* and of the ventral shields. 

 As the scaling of the l>ack and the coloration may well be derived from 

 the condition in L. viinpara, I have little doubt that the genus Tachy- 

 clromns is to be regarded as directly descended from an oriental species 

 of Lacerta connected with L. vivipara. 



■2. TACHYDEOMUS TACHYDROMOIDES. 



Lacerta tachydromoides, Schleg. Faun. Japon., Eept. p. 101, pi. i, 

 figs. 5-7 (1838). 



Tachydronms ja2}onicns,D\im. & Bihr. ^vY>. G6n. \, p. 161 (1839); 

 Giinth. Eept. Brit. Ind. p. 69 (1864) ; Hilgend. Sitzb. Cles. Nat. Fr. 

 Berl. 1880, p. 112. 



Tacliysaurusjaponicus, Gray, Cat. Liz. ]). 52 (1845). 



Tachydromus tachydromoides, part.,. Bouleug. Cat: Liz. iii, p. 5 

 (1887)." 



Tachydromus tacliydromoides, Giinth. Ann. & Mag. N. H. (6) i, 1888, 

 p. 169 ; Stejneger, Herp. Japan, p. 247, fig. (1907) ; Bouleng. Mem. 

 As. Soc. Beng. v, 1917, p. 212. 



Tachydromus hoJ^'ti, Bouleug. Proc. Zool. Soc. 1894, p. 733, pi. xlix, 

 fig. 1. 



Body feebly depressed. Head U to If times as long as broad, its 

 depth equal to the distance between the anterior corner of the eye and 

 the tympanum, its length 3| to 4 times in length to vent iu males, 4 

 to 4^ times iu females ; snout pointed, with strong cauthus and nearly 

 vertical loreal region, as long as the postocular part of the head. 

 Pileus li to 2 times as long as broad. Neck as broad as the head. 

 The hind limb reaches the axil, the shoulder, or the collar in males, the 

 wrist, the elbow, or the axil in females; foot 1 to li times as long as 

 the head. Tail 2 to 3i times the length of head and 1)ody (If times 

 in the very young) . 



Nostril pierced between three shields. Eostral not entering the 

 nostril, nearly always in contact with the froutouasal,t usually broadly ; 

 frontonasal as long as broad or slightly broader, as broad as the 

 internarial space or a little broader ; prefrontals forming a median 



* A character which has become fi.xed in T. sexlineatus, at the other end of 

 the series. 



t Two exceptions, male from Koshikn and female from Kciyosun, in -ivliich 

 the nasals meet behind the rostral. 



