92 
William E. Sanderson 
also suffered from extreme fading after preservation. Scalation clearly 
identifies both animals as cyclopion. Another specimen (LSUMZ 
15779) collected at the same time as LSUMZ 15780 has typical 
cyclopion ventral coloration. 
Cooper (1977) reported collecting an intergrade specimen in 
extreme southern Baldwin County, Alabama. This specimen was lost 
(W. E. Cooper, Auburn University, personal communication), but 
Cooper provided a second snake from this locality (LSUMZ 40089, 
Alabama: Baldwin County, Gulf Shores State Park, Lake Shelby) 
which he said has a ventral color pattern similar to that of the 
first specimen. In scalation, it is referable to cyclopion , but the 
ventral color is atypical in that the crescentic areas, which normally 
are cream to white in color, are nearly obliterated by blotches of 
dark pigment. I have seen two other specimens with similar atypi- 
cal patterns, both from Louisiana, and thus do not believe this col- 
oration to be indicative of intergradation. 
Although cyclopion and floridana have not been collected to- 
gether, the two forms do appear to be at least parapatric in the 
area along the Perdido River, the Alabama-Florida state boundary. 
My analysis reveals no clear evidence of gene exchange between 
the two taxa. Additionally, the work of other researchers has re- 
vealed significant biochemical differences between the two taxa. Pearson 
(1966) reported a “low relationship” between the taxa and suggested 
elevation to full species. More recently, Lawson (1987) employed 
starch-gel electrophoresis to assay 35 gene loci of Thamnophiine 
snakes and found fixed allelic differences between cyclopion and 
floridana at seven of these loci. He concluded that cyclopion and 
floridana are sister species, with the degree of separation being 
somewhat greater than that which separates Nerodia rhombifera and 
N. taxispilota. In light of this body of evidence, I concur with 
Lawson and support his proposal that Nerodia c. cyclopion and N. 
c. floridana be elevated to monotypic species, Nerodia cyclopion 
and Nerodia floridana , respectively. 
SPECIMENS EXAMINED 
Nerodia cyclopion — Alabama: AUM 3030, 19345—46, 22105, 22290, 
22448-52, 22455-59, 25970, 26618, 29371. CMNH 67353-55, 67385- 
86. LSUMZ 15779-80, 40089. MCZ 318. MMNS (AR)2424(A-C). 
NMNH 56259. UAHC 51-546, 53-14. UF 50399. USA 757, 1801, 
1929-32, 2074-76, 2127, 2194, 2227. Arkansas: UF 48036. NMNH 
56258. Florida: LSUMZ 40401-2. Illinois: INHS 8749, 10002. LSUMZ 
7543. NMNH 1639. Louisiana: LSUMZ 1566, 2839-43, 2846-47, 
2937, 4785, 8205-06, 10466, 12071, 12933, 12985, 13135-36, 13556, 
