CRANIAL CHARACTERS OF LACERTA JACKSONI. 31 



clasely allied to L. muralis, forma typica. It agrees with the 

 latter as well as with L. mosoreiisis in the strongly depressed and 

 more broadlj'^ expanded skull-structure in general. Also in the 

 widei- interorbital region, likewise a marked feature in Lacerta 

 vivipara. Also in the mode in which the connection between the 

 posterior portion of the parietal and that of the supraoccipital 

 presents itself ; in the absence of teeth on the pterygoid bones, 

 and in the degree of divergence of these latter, as well as in the 

 configuration of the basioccipital and the basisphenoid. Fiuther, 

 in the shortened muzzle with broadened base, and in the 

 anteriorly bi-oadened nasal process of the pnemaxillary bone 

 (text-fig. 6, D), well indicated in the typical form of L. muralis 

 from Turin (text-fig. 6,G), but assuming its widest proportions in 

 Lacerta agilis (text-fig. 6, I). 



The total absence of supraocular fontanelles, notwithstanding 

 the typically platycephalous structure, together with the onto- 

 genetically early complete fusion to one composite plate of the 

 postfrontals, would justify our referring this type of skull to the 

 group of Lizards to Avhich the term of Neolacei'tte * has recently 

 been given. 



However, considering the views held and recently enunciated 

 by writers on the subject of the phylogenetic relation of some 

 of these characters, it is luther surprising to find undivided 

 postfrontals also in species belonging to entirely dift'erent genera, 

 such as Eremias, as Prof. v. Mehely t regards that genus as one 

 of the prototypes of ai'chfeolacertic forms of this family because 

 of the character of its lepidosis. 



I might add that in Acant/iodactylns hoskianusX, a lizard to 

 which Siebenrock § ascribes a divided condition of the post- 

 frontals, I find them to be completely fused into one plate in the 

 skull of a female in the British Museum Collections. 



A perfectly obliterated suture between the two postfrontals 

 I also find in a female specimen of Scapteira knoxii, another 

 decidedly platycephalous species. 



Thus, beyond some more or less doubtful points in regard to a 

 satisfactory solution concerning the question of phylogeny, skulls 

 of females do not seem to afford trustworthy indications from 

 which to draw conclusions as to affinities. It is to that of 

 the male, so far as an examination of the present limited 

 material is concerned, that one must turn for better results. 



As pointed out in the detailed part of the description, the 

 tabular surface (inclusive of the postfiontals) is a very conspicuous 

 feature of this male skull when taken in conjunction with the 

 quadrangular and posteriorly well projecting parietal region. A 

 near approach in this respect is to be found in a male specimen 

 of Lacerta muralis of the variety lilfordi, a form restricted to 



* L. V. Mehelj-, Materialieii, 1. c. 



t li- X ^^"^ "ot stated by Siebenrnck. 



§ Cf. " Das Skelct der Lacerta simoiiyi" Sitzb. Akad. Wis!<. Wieii, 1894, p. 37. 



