150 Laoertidse. 



Measurements (in millimetres) : (?•(?•?• 



From end of snout to vent . . .45 53 57 



Length of head 11-5 14 13 



Width of head 65 — — 



Fore limb 18-5 22 22 



Hind liinl. 29 30 30 



Tail 85 102 173 



Hahifat. — Forest region of Central Africa, between Kagera and the 

 Congo, Kwidjwi Island in Lake Kivu, and Euanda, up to an altitude 

 of 2400 m. 



This species, which is only known to me from the descriptions and 

 figure Cjuoted above, has been regarded by Tornier as closely related 

 to L. jaclcsonii, by Sternfeld as nearer to L. vivipara. I am inclined 

 to agree with the latter author. It is a remarkable fact that, notwith- 

 standing the great differences in form and coloration which separate 

 them, the three tropical African species, L. jacJcsonii, vauereselli, and 

 echinata, agree in the absence of the parietal foramen. Is this 

 important morphological negative feature to be regarded as due to 

 convergence, connected with climatic conditions, or does it indicate 

 relationship ? I am for the present in favour of the former hypothesis. 



Section IV. Podaecis, Wagl. — Transverse series of ventral plates 

 with rectilinear or nearly rectilinear border, longitudinal series 6 or 8 

 in number; femoral poi-es 12 to 31; toes more or less compressed, 

 with 19 to 30 lamellar scales under the fourth. 



A. Normally a single postnasal.* 



1. Pterygoid teeth constantly or nearly constantly present. 

 An incomplete series of granules between the supraoculars and 



the superciliaries (rarely reduced to 2 to 5) ; collar serrated ; 

 dorsal scales usually diagonally keeled ; caiidal scales more 

 or less pointed behind ; 19 to 29 lamellae under the fourth 



toe L. tanrica. Pall., p. 152. 



Granules between the supraoculars and the superciliaries absent 

 (rarely 1 to 3) ; collar not serrated ; dorsal scales smooth or 

 feebly keeled; caudal scales truncate or very obtuselj' pointed 

 behind ; 26 to 31 lamella' under the fourth toe. 



L. pelopcninesiaca, Bibr., p. 159. 



2. Pterygoid teeth absent, with rare exceptions ; collar 



entire or feebly serrated, rarely strongly serrated. 

 A parietal foramen f ; dorsal scales, if distinctly hexagonal and 

 keeled, not larger than the laterals; ventral plates in (5 

 (exceptionally 8) longitudinal series . . L. vmralis, Laur., p. 162. 



* Exceptions rather frequent in L. muralis, var. hedriagx. 

 t Indicated externally by an impression or a light dot in the centre of the 

 interparietal shield. 



