by no more than one scale, but in some individuals they are
separated by two or more scales. Although the above data minimize
certain differences between the northern and southern populations of
this species, certain of the color pattern characters seem to be
diagnostic of the subspecies inhabiting the Pacific lowlands from
Guerrero to Nayarit. Large adults of _S. m. calligaster_ have only a
faint dorsal pattern, which in the subspecies _melanorhinus_ and
_stuarti_ consists of a series of large, dark, interconnected triangles
on the back. This pattern is present in young and small adults of _S. m.
calligaster_; furthermore, in this subspecies the ventral coloration of
the males differs from that found in the more southern populations.
Adult males of _S. m. calligaster_ have a black throat, that changes to
brilliant blue posteriorly, and a large white spot medially on the chin.
This spot is present in some specimens from Oaxaca and Chiapas, but, if
present, it is much smaller and less distinct than in specimens from
Michoacan. In _S. m. calligaster_ the chest and midventral area are
orange to salmon-color.

A male from Lombardia in life was colored as follows: Dorsum grayish tan
bearing faint bluish gray flecks; chest deep salmon-orange, this color
continuing down midventral area to the somewhat paler groin; belly
patches pale blue fading to pale green laterally; throat black
anteriorly enclosing a white spot; throat blue posteriorly and bluish
green posterolaterally.

Individual lizards were observed to change in dorsal color from a pale
ashy gray to a rather dull brown. Normally, inactive individuals and
those observed on overcast days were dull brown.

_Sceloporus melanorhinus calligaster_ is found in trees in riparian
situations in the lowlands to elevations of about 1500 meters. It does
not inhabit the arid tropical scrub forest in the Tepalcatepec Valley or
on the coast, but in those areas is found in the gallery forests along
streams and rivers. The lizards are wary and live high in the trees;
they are especially difficult to locate in the rainy season, when the
trees are in full leaf.

~Sceloporus pyrocephalus~ Cope

_Sceloporus pyrocephalus_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 16:177, September 30, 1864.--Colima, Colima,
Mexico.

Acahuato (2); Apatzingan (142); Arteaga (4); 26 km. S of
Arteaga (4); Capirio (6); Chinapa; Chupio; 19 km. S of
Corralito (5); El Sabino (2