der ' Muralis-F/-«^e.' " 43 



— Clariallabes — Gymnallabes — Channallales, in which we 

 witness the gradual disappearance of the plates which roof 

 over the sides of the skull, concurrently with the eel-like 

 elongation of the body, the reduction of the caudal fin, and 

 the reduction and ultimate suppression of the paired litis — a 

 most suggestive series, the direction of which is unmistakable. 

 Again, in the Cliaracinid fishes, as pointed out by Sagemehl, 

 the more primitive types, witii large toothed maxillary bone, 

 have a massive skull, the fontanelles appearing together with 

 the reduction Cf the maxillary bone. The same story is told, 

 in a somewhat different way, by Cheloniaus (Clielydra — 

 Staurotypus, Eniys — Cistudoy &c.). In Lizards, also, wheix 

 we have to deal with an unmistakable orthogenetic series, 

 the drift of which is open to no question, as in Chalcides, for 

 instance, the more generalized type has a more convex skull, 

 better protected by osteodennal plates. But there is another 

 point which is of great importance, and which Prof. v. 

 Mehely does not a))pear to have considered. The Lacertce 

 with massive skulls, from which I would assume the platy- 

 cephalous lizards to have been derived, have teeth on the 

 palate (pterygoid bones). These teeth are nearly constantly 

 ])resent in Lacerta taurica and constantly absent in the forms 

 of L. muralis with supraocular fontanelles mentioned by 

 Prof. V. Mehely. Now, the only cases in which 1 have found 

 teeth on the palate in L. muralis have been in examples of 

 the pyramidocephalous vars. campestris and serpa *, a fact 

 which, in my o])inion, goes a long way to support the view 

 of Eimer as to tiie general drift of evolution in this group of 

 lizards. 



Much as I value the careful investigation of neglected 

 ])oints of structure, whether external or osteological, to which 

 Prof. Mehely is devoting himself, I cannot help regretting 

 the too frequent appeals he makes to phylogeny in order to 

 give importance to characters which, from a strictly syste- 

 matic point of view, must be regarded as trivial and had 

 better be omitted from specific diagnoses. I have pointed out 

 on various occasions f that some of the lepidosis characters on 



* I have looked for these teeth in a large number of examples of the 

 typical form without ever succeeding in tiuding any. Siebeurock (Sit/.b. 

 Akad. ^Vien, ciii. i. 1894, p. 2-54) must therefore, in all probability, have 

 had skulls of some other form before him when he wrote tliat six or 

 seven pterygoid teeth are present in L. muralis. As his specimens are 

 stated to be from Dalmatia, it is most likely that they belong to one of 

 those pyramidocephalous forms which were grouped oy Bedriaga under 

 L. viuralis neapolitunn. 



t Proc. Zool. Soc. 1904, ii. p. 333 ; Nov. Zool. xii. 1905, p. lo ; Trans. 

 Zool. Soc. xvii. 1905, p. 351. 



