7) actually are
sulphur-yellow in life.

~Loxocemus bicolor~ Cope

_Loxocemus bicolor_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 13:77, June 30, 1861.--La Union, El Salvador.

_Loxocemus sumichrasti_ Bocourt, Ann. Sci. Nat., ser. 6,
4:1, 1876.--Tehuantepec, Oaxaca, Mexico.

Apatzingan (6); La Orilla; Lombardia.

As noted by Peters (1954:21), this species was not recorded from
Michoacan by Smith and Taylor (1945:27), but Gadow (1930:30) collected a
specimen at La Orilla in 1908. This specimen (BMNH 1914.1.28.124) is a
male having 235 ventrals and 47 caudals, a dark brown dorsum, and
cream-colored labials and venter. The anterior chin-shields are
considerably longer than the scales bordering the chin-shields. In these
characters this specimen agrees with the diagnosis of _Loxocemus
bicolor_ given by Taylor (1940c:447), who revived _Loxocemus
sumichrasti_ Bocourt. Of the six specimens from Apatzingan in the
Tepalcatepec Valley, three males have 243 to 253 (246.6) ventrals and 44
to 45 (44.3) caudals; three females have 238 to 247 (244.0) ventrals and
42 to 44 (43.0) caudals. Certain characters of scutellation utilized by
Taylor for separating _L. bicolor_ and _L. sumichrasti_ are inconsistent
in this series. The chin-shields are longer than the adjacent scales,
like those illustrated in _L. bicolor_ by Taylor (_op. cit._, fig. 1).
The relative lengths of the prefrontal and internasal sutures are
subequal, or the prefrontal suture is slightly longer. Thus, in these
characters of scutellation these snakes are like _L. bicolor_, but in
coloration they are like _L. sumichrasti_; the dorsal color in life was
an iridescent dark bluish gray, and the belly was pale gray or bluish
gray.

The supposed differences in scutellation between _L. bicolor_ and _L.
sumichrasti_ have been questioned by Woodbury and Woodbury (1944:360);
these authors treated _L. sumichrasti_ as a subspecies of _L. bicolor_.
As pointed out by Zweifel (1959b:5), such an arrangement is not tenable,
for, although individuals with each kind of color pattern have not been
collected together at any one locality, the over-all geographic picture
is one of sympatric distribution. Only snakes having the coloration of
_L. sumichrasti_ have been collected in the Balsas-Tepalcatepec Basin. I
agree with Zweifel (_loc. cit._) that on the basis of morphological
similarities and sympatric distribution, _L. bicolor_ and _L.
sumichrasti_ seem t