ions of about 1050 meters (approximating the lower limits of the
oak forest). The record from Uruapan (USNM 10234, collected by Duges) is
doubtful.

These large lizards are most easily observed on rock fences along roads.
Near Apatzingan innumerable individuals can be seen in mid-morning.
Later in the day, as the sun rises higher in the sky, the lizards
retreat to the shade of the crevices in the fences. The abundance of
these lizards in the Tepalcatepec Valley, together with evidence
gathered from the natives of the valley, indicates that these lizards
are seldom used for human consumption there. On the other hand, several
people in Coalcoman consider the "iguana negra" (local name for
_Ctenosaura_) to be a delicacy and serve it at every opportunity. In
early July, 1951, brilliant green young of the year were collected at La
Playa and at Coalcoman.

~Enyaliosaurus clarki~ (Bailey)

_Ctenosaura clarki_ Bailey, Proc. U. S. Natl. Mus., 73:44,
September 26, 1928.--Ovopeo (= Oropeo), Michoacan, Mexico.

_Enyaliosaurus clarki_, Duellman and Duellman, Occ. Pap.
Mus. Zool. Univ. Michigan, 598:1, February 16, 1959.

Twelve km. SSW of Apatzingan; Capirio (7); Cofradia (3); El
Espinal (2); 32 km. E of Huetamo; Jazmin (5); Oropeo (10);
Rancho Nuevo; Rio Cancita, 12 km. E of Apatzingan (8);
Tepalcatepec (3); Zicuiran (6).

This species is known only from the low areas of the Balsas-Tepalcatepec
Basin between elevations of 200 and 510 meters. It is commonly found in
the open arid tropical scrub forest dominated by _Prosopsis_ sp.,
_Apoplanesia paniculata_, and _Cercidium plurifoliolatum_. Continued
collecting in the Tepalcatepec Valley has borne out the suggestions of
Duellman and Duellman (1959) concerning the distribution and abundance
of this lizard. Also, continued collecting in Colima and on the Pacific
coast has failed to reveal the presence of _Enyaliosaurus_ there.

~Phrynosoma asio~ Cope

_Phrynosoma asio_ Cope, Proc. Acad. Nat. Sci. Philadelphia,
16:178, September 30, 1864.--Colima, Colima, Mexico.

Apatzingan (4); San Salvador.

In Michoacan this species has been obtained only in the Tepalcatepec
Valley and on the northern slopes of the Sierra de Coalcoman between 300
and 700 meters. Apparently the lizard is absent from the coastal
lowlands of Michoacan and Guerrero. The distribution of this species,
therefore, is discontinuous. One population inhabits