376 MR. a. A. BOULENGER ON THE VARIETIES OF 



1. 2. 3. 4. 5. 6. 



S . I. del Ayre 72 78 28 10 39 23 



64 90 27 11 36 23-22 



64 83 27 10 31 20 



$ . „ 64 80 30 10 35 20 



61 80 27 10 38 20-19 



„ „ 53 88 27 13 40 21 



<J . I. Dragoueras 64 77 27 13 37 24-23 



56 75 29 10 32 24 



S . I. la Guardia 62 76 23 14 32 18-19 



62 85 26 12 35 19 



„ „ 60 86 26 15 36 22-21 



?. „ 56 70 28 11 30 17 



52 72 27 15 32 19-20 



51 79 28 14 34 18-17 



Specimens from Mahon are figured on Pis. XXIII. fig. 1 and XXVI. fig. 6. 

 One of the types of Z. lilfordi from Ayre Island is represented on PL XXVI. fig. 7. 



The absence of any trace of a keel on the dorsal scales distinguishes this variety from 

 the preceding as well as from the vars. serpa and tiliguerta. 



IV.— ITALY and SICILY. 



A. Typical form, var. breviceps Blgr., var. beueggemanni Bedr., 

 and var. nigkiventkis Bonap. (Plates XXIL, XXIIL, XXIV., XXVIII.) 



In dealing with the variations of the Wall-Lizards in Central Europe, we have had 

 no difficulty in satisfying ourselves that, however great the differences between 

 individuals brought together under the name of L. muralis, we are not mixing up 

 forms which, if better understood, might be regarded as distinct species or subspecies, 

 and that even if any of the differences noticed should prove constant in a district, we 

 are only uniting under one name local or geographical variations for the future 

 recognition of which the name of the species coupled with the locality is amply 

 sufficient. But as soon as we extend our investigations south of the Alps, the problem 

 becomes more difficult, and we find ourselves confronted with several more or less 

 distinct forms, which, as they sometimes occur side by side in a locality, it is imperative 

 to distinguish by different names — be they called species, subspecies, races, or varieties. 



On the rank to be accorded to such forms, the opinions of the best herpetologists 

 have differed very considerably in the past. 



In the last revision of these lizards 1 I have, following the lead of the highest 



authority on this difficult subject, grouped the Wall-Lizards of Italy under three 



headings : the forma typica (subsp. fusca Bedr.), var. brueggemanni Bedr. (on 



* 



1 Cat. Liz. iii. p. 28 (1887). 



