208 G. A. BOULENGER ON 
Head shields normal.' Nostril pierced between the nasal, one or two post- 
nasals, and the first upper labial. Lower eyelid scaly. Collar more or less distinct 
or absent. Back with large plate-like subimbricate scales with strong keels forming 
continuous lines; sides with small juxtaposed or granular scales; ventral plates more 
or less imbricate, often pointed and keeled. Digits cylindrical or slightly compressed, 
with smooth or somewhat tubercular lainelle inferiorly. Femoral pores reduced to 
one* to three. Tail long or extremely long, cylindrical. 
Eastern Asia. 
The parietal foramen is constantly present and pterygoid teeth are absent or 
reduced to 2 to 5. 
The term ‘inguinal pores’ has been universally used for the one or two pores on 
each side of the praeanal region, as is the rule in this genus, and no exception could 
be taken to this terminology were it not that when more than two pores are present, 
the series extends on to the thigh. As the single pore is part of the series known as 
femoral pores in the other Lacertide it is more logical, in view of securing a uniform 
terminology, to discard the term ‘inguinal’ and to express the state of things in 
Tachydromus by saying that the series of femoral pores is reduced to one to three. In 
several forms of Lacerta and Latastia, when the number of femoral pores falls very 
low, the reduction takes place from the distal end of the thigh, thus leading to the 
condition in Tachydromus, as specimens of Lacerta vivipara and Latastia longicaudata 
with only five femoral pores show very clearly. It is also noteworthy that in the 
African analogue of Tachydromus, Poromera, Blgr., the series of femoral pores, though 
a long one, ends at some distance from the knee-joint. 
SYNOPSIS OF THE SPECIES. 
I. Head not more than 1} times as long as broad. 
A. 4 supraoculars, first very small (rarely absent) ; 
dorsal plates in 5 to 8 longitudinal series, ven- 
trals in 8 or Io. 
I. 4 or 5 pairs of chin-shields (very rarely 3) ; 
ventral plates in 8 longitudinal series, feebly 
keeled or all except the outer smooth ; 29 to 40 
plates and scales round middle of body. 
Dorsal plates in 7 or 8 longitudinal series; ventral 
plates in 22 to 28 transverse series ; 3 femoral pores 
on each side ; rostral in contact with frontonasal ; 
tail 12 to 24 times length of head and body .. I. I. amurensis, Peters. 
Dorsal plates in 5 to 7 longitudinal series ; ventral 
plates in 22 to 25 transverse series ; 2 (very rarely 3) 
femoral pores on each side ; rostral nearly always in 
. a frontonasal, a pair of priefrontals, a frontal, a pair of frontoparictals, a pair of parietals, an interparietal, 
and an occipital. 
2 Inguinal pore, 
