388 ME. G. A. BOULENGER ON THE VAEIETIES OF 



that of the var. serpa, as may be seen by a tabulation of the number of scales in 

 specimens of the different varieties and local forms : — 



Var. brueggemanni 

 Var. nigriventris, Rome . 

 Var. serpa, Rome, Naples 

 Malta . . 

 Var. filfolensis, Filfola . 



1. Number of dorsal scales in a transverse series. 2. Transverse series of dorsal scales 

 corresponding to length of head. 3. Number of gular scales in a longitudinal series. 

 4. Number of femoral pores. 5. Number of lamellar scales under fourth toe. 



1. 



2. 



3. 



4. 



5. 



51-65 



35-52 



22-30 



17-25 



24-28 



55-71 



37-51 



22-29 



18-23 



27-31 



58-76 



38-55 



22-31 



18-27 



28-33 



61-71 



40-58 



29-35 



19-25 



30-34 



68-82 



43-62 



29-38 



18-27 



31-36 



B. Vars. campestris Betta and serpa Baf. 

 (Blates XXIII., XXVII., & XXVIII.) 

 The forms to be described here have frequently been confounded, or grouped 

 together under the same general designation, as by Bedriaga (L. muralis neapolitana), 

 Camerano (L. serpa), and myself (var. tiliguerta). But it is really possible to dis- 

 tinguish a northern and a southern form — the former, var. campestris, being more 

 sharply differentiated from the typical form, with its vars. brueggemanni and nigri- 

 ventris, than the latter. While concentrating their attention on the colour, the 

 markings, and the shape of the head, characters far less stable than one would gather 

 from their writings, Bedriaga and Eimer have somewhat neglected the lepidosis, 

 which, however subject to fluctuations within very wide limits, affords a safer means 

 of defining forms. If the lepidosis be taken into consideration, together with the 

 other characters, it will be found that, after elimination of the typical form and 

 the two varieties into which it gradually transforms from north to south, two further 

 varieties can be separated with sufficient precision. If we could put aside the 

 more northern of the two latter, the var. campestris, we should feel perfectly 

 justified in saying, that the Wall-Lizard passes gradually, at least so far as structural 

 characters are concerned, from the typical form in the north to the var. serpa in the 

 south, the drift of variation from north to south being in the direction of a larger size, 

 a shorter body, smaller scales, longer toes, and smaller scales. But this continuous 

 series is broken, or obscured, by the presence, from the plains of North Italy to the 

 Roman province, of the var. campestris, which, further south, gradually passes into the 

 var. serpa, especially as regards the coloration. 



I fully agree with Eimer in regarding the striated type of the var. campestris as the 

 most primitive of all the W T all-Lizards, and I am quite prepared to admit, so far as 

 such speculations based on theoretical conceptions are allowable, that it has given rise, 

 or at least is most nearly related, to the form that has become modified into both the 



