o be dimorphic phases of the same species, showing no
more striking differences in coloration than _Lampropeltis getulus
californiae_, a now classical example of pattern dimorphism in snakes.

In Michoacan, as in other parts of its range, _Loxocemus bicolor_
inhabits arid scrub forest environments at low elevations.

~Boa constrictor imperator~ Daudin

_Boa imperator_ Daudin, Hist. nat.... des reptiles, 5:150,
1803.--Mexico. Type locality restricted to Cordoba,
Veracruz, Mexico, by Smith and Taylor (1950a:347).

_Boa constrictor imperator_, Forcart, Herpetologica, 7:199,
December 31, 1951.

Apatzingan (4); Coalcoman; El Sabino (2); La Placita; La
Playa (2); Lombardia; Nueva Italia (2); Rio Cachan; Rio
Marquez, 13 km. SE of Nueva Italia; Rio Nexpa; Volcan
Jorullo.

These specimens have come from a variety of habitats from elevations of
less than 1,000 meters. The species seems to be equally abundant in the
broad-leafed semi-deciduous forests of the coastal foothills and in the
arid Tepalcatepec Valley. In the latter area most of the specimens were
collected at night.

~Coniophanes fissidens dispersus~ Smith

_Coniophanes fissidens dispersus_ Smith, Proc. U. S. Natl.
Mus., 91:106, November 13, 1941.--El Limoncito, Guerrero,
Mexico.

Arteaga.

Further collecting in southern Michoacan has failed to add additional
material of this species, which is known in the state from the one
specimen collected by Gadow in 1908. The species possibly ranges
throughout the coastal foothills of the Sierra de Coalcoman. Peters
(1954:21) described the specimen from Arteaga.

~Coniophanes lateritius lateritius~ Cope

_Coniophanes lateritius_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 13:524, March 31, 1862.--Guadalajara, Jalisco,
Mexico.

_Coniophanes lateritius lateritius_, Smith and Grant,
Herpetologica, 14:20, April 25, 1958.

Nineteen km. S of Arteaga.

The one specimen available from Michoacan of this apparently rare
species was discussed by Wellman (1959:127), who pointed out that
although the specimen was geographically intermediate between the
subspecies _C. l. lateritius_ (Jalisco and Nayarit) and _C. l.
melanocephalus_ (Morelos and Puebla), the specimen (UMMZ 118954) was
like _C. l. lateritius_ in scutellation and in color pattern differed
from other known specimens of the species in having had in life a pale
oran