REVISION OF THE KING SNAKES. 



211 



Reference to the accompanying table of geographic variation 

 shov.'s that the averages for ventral jilates are highest in the region 

 from New Orleans to Florida and near Kaleigh, lower at the Oke- 

 finokee Swam.]), and lowest in southern Florida. Tiie maxmia and 

 minima are correlated with the averages — the lowest number occurs 

 at Lemon City and the highest at Mobile. Precisely the same situ- 

 ation holds with regard to the infralabials, and this is closely paral- 

 leled by the presence or absence of the loreal. The scale rows, too, 

 show the same relation to locality. While the formula is corajnonly 

 17-19-17, it is very noticeable that 19-17 or 19-20-19-17 appears 

 in the extreme western portion of the range, and in the extreme 

 north, while in penhisular Florida nothhig higher than 17-19-17 has 

 been noted (except one hidividual, said to be from Marion County, 

 which has the unusual formula 18-21-19-17); at Lemon City 17 rows 

 throughout have been noted m 3 specimens, 17-15 in 2, and 15-17-15 

 in 1. 



Table showing geographic variation in elapsoides. 





Num- 

 ber of 

 speci- 

 mens. 



Ventral plates. 



Loreal. 



Infralabials. 



Locality. 



Extremes. 



Aver- 

 age. 



Pres- 

 ent. 



Ab- 

 sent. 



Extremes. 



Aver- 

 age. 



New Orleans to western Flor- 

 ida 



8 



6 



10 



11 



168-193 

 170-185 

 173-186 

 152-180 



180 

 176 



5 



3 



1 

 2 

 6 



8-9 

 8-9 

 8-9 

 7-9 



8.63 



Okefinokee Swamp 



8.15 



Raleigh, North Carolina 



Lemon City, Florida 



181 1 8 

 172 5 



8.38 

 7.95 















It seems quite evident that the tendency to reduction in size and 

 scutellation has been able to proceed faster in the most isolated 

 portion of the range, that is, Florida. We can not doubt that the 

 form as it occurs here is a direct derivative of the same as it occurs 

 in Georgia and Alabama, for the reason that Florida is geologically 

 too recent to be a region of preservation of animal types. For this 

 reason and because the only difference between the Florida ela'psoides 

 and the same from the region north of Florida is that the former 

 attauis lower structural limits and averages than the latter, we must 

 conclude that evolution in this form is here proceedmg hi the direc- 

 tion of reduction or degeneration. When therefore we see elapsoides 

 in Alabama presenting such an approach and close resemblance to 

 a nearly related form, overlappmg in individual instances every 

 difference between the two, we can not but conclude that the same 

 processes by which elapsoides is bccomhig changed in Florida have 

 operated to evolve elapsoides from amaura. A study of all the 

 material available shows that the structural differences between them 

 are only such as would result from hitensification of degenerative 



