Storeria Variation 
97 
ANALYSIS OF CHARACTERS 
Head Pattern. —Specimens of Storeria occipitomaculata frequently 
darken if left in formalin for even a few days, so we were not able to 
determine natural head coloration in many of the individuals we ex- 
amined. Nevertheless, it is apparent that snakes having a very dark head 
that contrasts with a lighter dorsum are not confined to the originally 
described range of S.o. obscura, but occur in coastal plain populations 
from at least South Carolina through Louisiana. Many of these same 
populations do, however, also contain animals whose head does not con- 
trast markedly with the dorsum, hence we question the taxonomic 
usefulness of this character. 
The presence or absence of a dark bar separating the light 
supralabial spot from the edge of the lip is virtually impossible to deter- 
mine in formalin-darkened specimens, and we lack these data for the ma- 
jority of specimens examined. 
Nuchal Pattern. —Although Storeria occipitomaculata obscura was 
characterized as having a complete light nuchal collar as opposed to the 
three light nuchal spots of S.o. occipitomaculata, 25% of the specimens we 
examined (9 of 36) from the described range of S.o. obscura have separate 
spots rather than a complete collar. Moreover, a complete collar occurs 
fairly frequently in most coastal plain populations (for instance in 10 of 
13 animals from the Florida Parishes of Louisiana and 15 of 27 from 
west-central Louisiana.) 
A more consistent character for distinguishing the coastal plain pop- 
ulations from their more northern counterparts is whether or not the 
light nuchal marks (spots or collar) are in contact with the light colora- 
tion of the venter (see Fig. 2). Such contact on both sides of the neck oc- 
curs in nearly all specimens examined from Florida, western Georgia, 
Alabama, Mississippi, Louisiana, eastern Texas, and southern Arkansas. 
In northern Arkansas, Tennessee, and extreme northern Alabama the 
frequency of animals having the light nuchal marks separated from the 
venter on at least one side of the neck ranges from 84 to 100%. Farther 
east, in northern Georgia and North Carolina, the frequency ranges from 
60 to 75%. In the geographically intermediate areas (southeastern 
Oklahoma, western Tennessee, eastern Georgia, and South Carolina) the 
light nuchal marks are separated from the venter in 27 to 50% of the 
animals. 
Ventral Coloration. —For reasons previously cited we have relatively 
sparse information about ventral color in living S. occipitomaculata. 
Nonetheless, from our personal observation and from color notes and 
color transparencies provided by other workers, we can say that the 
coastal plain snakes rarely have the bloodred or crimson venter typical of 
the nominate race. Instead, ventral color may range from lemon yellow 
through pale orange to butterscotch tan. 
