90 
William E. Sanderson 
could have resulted in artificially dissimilar values. The distributions 
of the female cyclopion groups, with somewhat larger samples sizes, 
were not significantly different. Further, the distributions of the dis- 
criminant scores of the two taxa do not overlap (Fig. 3). I con- 
clude there is a lack of gene flow between parapatric populations 
of cyclopion and floridana. Continued investigation, ideally with ad- 
ditional specimens of floridana from this critical area, is definitely 
warranted. 
Distribution 
Fieldwork undertaken to clarify the distribution of green water 
snakes in western Florida was largely unsuccessful. Collecting trips 
to this area produced no specimens of N. floridana and only one 
N. cyclopion (Louisiana State University Museum of Zoology 40401, 
Florida: Escambia County, Perdido Bay Golf Club). Another cyclopion 
from the same locality (LSUMZ 40402) was procured for me by a 
local collector. The presence of this population in Escambia County 
indicates that N. cyclopion should be considered a resident of the 
state of Florida, although Ashton and Ashton (1981) did not in- 
clude cyclopion in their work on the snakes of Flordia. 
Carr (1940) reported Nerodia cyclopion cyclopion from Leon 
County, Forida. These specimens could not be located and are pre- 
sumed lost, and Carr was not certain that they were cyclopion (P. 
Meylan, University of Florida, personal communication). The westernmost 
specimen of floridana (AUM 6087, Florida: Escambia County, Perdido 
River at Seminole) has an atypically dark venter when compared 
with specimens from the Florida peninsula. However, scale data identify 
it as floridana with a very high level of confidence ( P = 0.999). 
The green water snake remains unknown from Santa Rosa and Okaloosa 
counties, Florida, although a specimen clearly referable to floridana 
was taken in Walton County near the Okaloosa-Walton County boundary. 
Given the specimens presently available, it appears that the distribu- 
tions of cyclopion and floridana are adjacent or overlapping in Escambia 
County, Florida (Fig. 4). 
DISCUSSION 
Specimens intermediate between Nerodia cyclopion and N. floridana 
have been reported twice from southern Alabama. Mount (1975) 
reported a population of green water snakes in extreme southeastern 
Baldwin County that he considered to be intermediate on the basis 
of ventral coloration. Although some of these animals do have ven- 
ters that are somewhat lighter than cyclopion from more inland parts 
of Baldwin County, they are very similar to specimens from other 
Gulf coastal regions, especially those from coastal Mississippi and 
