124 BRITISH LIZARDS 



e.g. C. sexlineatus, never abandon the colouration of 

 the young of other species and subspecies. When 

 there is a distinct modification in colour marking due 

 to age, the process is as follows : — The young are 

 longitudinally striped from two to four stripes on each 

 side of the middle line. With increasing age, Hght 

 spots appear between the stripes, in the dark inter- 

 spaces. At a later stage these spots increase in trans- 

 verse diameter, breaking up the dark bands into spots. 

 In some of the forms these dark spots extend them- 

 selves transversely and unite with each other, forming 

 black cross stripes of greater or less length. Thus we 

 have before us the process by which a longitudinally 

 striped colouration is transformed into a transversely 

 striped one, as age advances. 



Another case in which the striped colouring of the 

 young is replaced by spots in the adults and old 

 specimens, is to be found in C. tessalatus, the process 

 being similar to that just described. 



We noted previously some sex variations in the 

 Scincidae. This family also exhibit striking variations 

 due to age. Indeed, Professor Cope states that all the 

 North American skinks lose their distinctive marks of 

 colour with age. All are dark, nearly black, when 

 young, varied with white lines or spots, which leave a 

 trace of their presence when old. Three of the labials, 

 the upper especially, are black with white centres. 

 There is always retained a dusky border to the lateral 

 edges. If the edge of the upper jaw be white, the 



