■ager' 41 



platyceplialous tliaii tliat of tlie tyjjical L. muralis, vvliich 

 falls in the platyceplialous group of M^liely. Besides, tlie 

 works of Eimer and o£ Bedriaga sliow^ in several instances, 

 that these authors have been unaLle to correctly appreciate 

 the character to which, in my opinion, they have attached too 

 great importance *. 



Yet, when we compare extreme forms, such as var. cam- 

 pestris or Jiumana J on the one hand, and var. Bedruigre'f or 

 sardua on the other, the difference in the two types of heads 

 stands out very strikingly. We are not much the wiser when 

 the skulls have been ))repared, as the characters pointed out 

 by Prof V. M^liely are, for the most part, correlative of the 

 degree of elongation or depression of the head, which can be 

 ajjpreeiated without injuring the specimens. It must be 

 borne in mind that skulls of lizards cannot be extracted as we 

 do in the case of mammals. Preparing the skull means the 

 partial destruction of the specimen, and in a discussion of 

 this kind, dealing mainly with individual variations, annectant 

 examples cannot always be sacrificed. Prof. v. I^lehely has 

 given us figures of two extreme types of skulls, but I could 

 easily lay out a series that would to such an extent bridge over 

 the differences as to show of how little practical value they 

 are for the definition of species, A discovery of Prof. v. 

 Mdhely's is the incomplete ossification of the supraocular 

 region in the most pronounced platyceplialous wall-lizards. 

 But even here he is obliged to make this restriction — that in 

 some, in the var- Bedriagce, for instance, the fontanel le in the 

 supraocular bony plates is "nicht immer vorhanden " in adult 

 males. The character is therefore not of so great importance 

 after all. 



What surprises me most is to find that Prof. v. IMehely 

 is not at all aware of the individual variations whicli occur in 

 the skulls of the forms which he classifies as ''rein l)laty- 

 cephal" and "rein pyramidoccphal." Thus he attaches a 



* For instance, in the vars. nit/riventris, serpa, and qvadriliiieata, some 

 specimens have been referred b^^ Bedriaga to the pyramidocephalous 

 group (Z. muralis neapolitana, Bedr.) and others of the same race to tlie 

 phitycejihahnis (L. viuraUs fusca, Bedr.). Eimer regards the Maltese 

 lizard as platycephalous and its Filfola derivative as pyramidoceplialdus, 

 a distinction which is not borne out by tiie material at niv disuosal. 

 Werner has also fallen into tlie same pitj in de^cribinn- examples of tlio 

 same form {L. viuralis litforalin, Werner) under the two groups (vars. 

 lUmna imdjiumana). I myself do not blush at confessing similar errors, 

 due, ]ierh:ips, more to the nature of tilings than to any want of " Scharf- 

 bliok ' on my part. 



t Prof. v.*M6hely calls this lizard L. reticulata, Bedr. But tins name 

 is otherwise employed in the genus Lacerta (^L. muralis ntivuluta, 

 Schreiber, Eimer). 



