674 Lonnberg, Variation and distribution of the smooth snake in Sweden. 



known limits of variation in number of ventral shields are 153 199 

 and of subcaudal shields 42 70 and thus the Swedish specimens are 

 intermediate forms in this respect. 



The shape of the plates of the head is varying- as well, and above 

 all, the rostral has a different shape in different specimens. As Bou- 

 lenger has stated, the \ax.fitzingeri is not only confined to Italy, 

 but is found later in Portugal, Spain and Austria, and even in Eng- 

 land. In Nr. 1, 3, 5 and 7 of the above mentioned specimens the upper 

 portion of the rostral measures fully two thirds or more of its distance 

 from the frontal. Thus these specimens come within the limits of the 

 mentioned variety which at the same time gets reduced to merely an 

 individual variety instead of its former rank as a geographical one. 

 In the other specimens the upper portion of the rostral measures from 

 one third to one half of its distance from the frontal. According to 

 Boulenger on his specimens the character from the rostral is com- 

 pletely deprived of any correlative of any other, either in the lepi- 

 dosis or in the coloration, and this is the case with the Upsala speci- 

 mens too. The shape of the frontal is different as well, sometimes 

 nearly triangular Avith the base forwards sometimes hexangular with 

 anterior angle. Other plates are normal in number and shape in all 

 8 specimens. 



Three figures showing different stages of development of the rostral plate in 

 Swedish specimens of the smooth snake. 



The coloration is different however in different specimens. Six 1 -) 

 specimens are grayish brown with a double row of dark spots on the 

 back, and a row of smaller similar spots on each side. Sometimes 

 there is a lighter stripe on the back between both rows of spots. 

 Often there is a dark stripe on each side of the head from nostril 

 through eye, extending on the sides of the neck corresponding to the 

 lateral row of spots. In specimen Nr. 8 this is obsolete and the lateral 

 row of spots is reduced to a the faint dusky line. On the posterior 

 part of the head there is a large blackish brown blotch corresponding 

 to both dorsal rows of spots but not confluent with them. Forehead 

 mottled with darker. Belly blackish, in the middle mottled with darker, 

 towards the sides speckled with white and black. Four specimens 

 are more distinctly brown, partly coppery. The lateral spots can not 



1) For the comparison of the colour of different individuals I have two 

 moie mutilated specimens thus 10 in all. 



