Lacerta. 151 



A parietal foramen ; dorsal scales more or less distinctly hexa- 

 gonal and keeled, larger than the laterals ; ventral plates 

 in 6 longitudinal series ; collar serrated ; 27 to 32 lamellse 

 under the fourth toe . . L. chlorogaster, Blgr., p. 292. 



No parietal foramen ; ventral plates in 8 longitudinal series ; 

 collar not or but slightly serrated ; 22 to 26 lamellse under 

 the fourth toe . . . L.jacksonii, Blgr., p. 295. 



B. Normally two superposed postnasals*; collar not or but feebly serrated. 



1. Pterygoid teeth constantly or nearly constantly present. 

 Ventral plates in 8 longitudinal series ; masseteric shield present; 



50 to 55 scales across middle of body, smooth ; 25 or 26 



lamellse under the fourth toe L. irandtii, De Fil., p. 299. 



Ventral plates in 6 (rarely 8) longitudinal series; masseteric 



shield large ; 49 to 62 scales across middle of body, keeled ; 



27 to 35 lamellse under the fourth toe . . L. Isevis, Gray, p. 302. 



Ventral plates in 8 longitudinal series ; temple covered with 



minute granules, which are smaller than the dorsal scales ; 



85 to 95 scales across middle of body, smooth or faintly 



keeled ; 29 or 30 lamellse under the fourth toe L. jayakari, Blgr., p. 307. 



2. Pterygoid teeth absent, with rare exceptions. 



a. A large upper temporal. 



52 to 66 scales across middle of body ; median subcaudal scales 

 not enlarged ; 27 to 32 lamellse under the fourth toe. 



L. danfordii, Gthr., p. 309. 

 59 to 75 scales across middle of body ; median subcaudal scales 

 strongly enlarged, the largest at least twice as broad as 

 long ; 22 to 26 lamellse under the fourth toe. 



L. oxycephala, J). & B., p. 819. 

 36 to 45 scales across middle of body ; median subcaudal scales 

 feebly enlarged ; 22 to 25 lamellse under the fourth toe. 



L. mosorensis, Kolomb., p. 323. 



b. Upper temporal and masseteric shields absent ; 



54 to 81 scales across middle of body. 



L. dugesii, M.-Edw., p. 327. 



Two postfrontal bones are present in tlie young of all the species of 

 this section, so far as they have been examined, but they have been 

 observed to fuse to one in adult specimens of L. muralis, vars. campestris 

 and albiventris, L. jacJcsonii, L. Isevis and L. dugesii. 



The division of this Section into two groups, according to the 

 presence of one or of two postnasal shields, is merely for convenience.t 



* Exceptions rather frequent in L. mosorensis. 



t As stated in the Introduction, p. 31, I take the single postnasal to be the 

 more primitive j but although the division of the shield into two has become 

 fixed in the forms which I regard as evolved out of L. parva, I believe that 

 a reversion by fusion to a single shield may have taken place in this case, as 

 the tendency in L. mosorensis shows. 



