98 
Douglas A. Rossman and Robert L. Erwin 
Fig. 2. Lateral view of left side of head and neck in Storeria occipitomaculata oc- 
cipitomaculata (above) and S.o. obscura (below) showing the differences in nuchal 
pattern. 
Relative Tail Length. —As can be seen from Fig. 3, the tail is propor- 
tionally longer in the coastal plain populations than in those farther in- 
land. The longest tail occurs in animals from the Florida Panhandle, 
southern Alabama, and southern Mississippi. 
Ventrals. —The number of ventrals exhibits no consistent differences 
between coastal plain and inland populations (see Fig. 4). Ventral num- 
ber is markedly higher in Louisiana, southern Arkansas, and eastern 
Texas, a trend that may reflect the closer geographical proximity of those 
populations to the Mexican S.o. hidalgoensis Taylor, which has even 
more ventrals and exhibits an increasing north-south dine therein 
(Trapido 1944; pers. obs.). 
Suhcaudals. -As might be anticipated, geographic variation in sub- 
caudal number (see Fig. 5) parallels that exhibited by relative tail length. 
In this instance, however, the coastal plain populations from Georgia, 
South Carolina and North Carolina agree more closely with inland pop- 
ulations than they do with the coastal plain snakes from farther south 
and west. 
