One of the large males displayed a defensive behavior prior to capture. When first observed the lizard was clinging to a tree trunk about one and one-half meters above the ground. When I approached, the lizard turned its flanks towards me; then it flattened the body laterally, extended the dewlap, opened its mouth, and made short rushing motions. When touched it bit viciously. On the ground these lizards have a rather awkward bipedal gait that is much slower than in _Basiliscus vittatus_. In life an adult male (KU 55804) was reddish brown dorsally with dark chocolate brown markings; the venter was creamy white, and the iris was dark red. The natives call this lizard _piende jente_. =Iguana iguana rhinolopha= Wiegmann Río San Román, 2. The _iguana_, as this lizard is called locally, seems to be uncommon in the forested areas of southern El Petén. Possibly this is due to the fact that the flesh of this lizard is relished as food by the natives. My two specimens were in large trees at the edge of the river. =Laemanctus deborrei= Boulenger Chinajá, 1; Toocog, 5. On June 26 a female having a snout-vent length of 129 mm. and a tail length of 502 mm. was found on a bush in the forest. The lizard, when approached, faced the collector and opened its mouth. In life the dorsum was bright green; the lateral stripe was white, and the iris was yellowish brown. This specimen contained four ova having lengths of 13.4 to 14.2 (average 13.9) mm. On June 30 at Toocog five white-shelled eggs were found in a rotting log. Measurements of the eggs are--length, 23.5 to 25.0 (average 24.2) mm.; width, 15.0 to 15.5 (average 15.4) mm. These eggs hatched on August 30. The five young had snout-vent lengths of 43 to 45 (average 44) mm., and tail lengths of 137 to 140 (average 138) mm. In life the hatchlings had a dull dark green dorsum, pale bright green venter and stripes on head, and reddish brown iris. In preservative the hatchlings are creamy tan above with five or six square dark brown blotches middorsally. The natives consider this lizard to be one of the anoles; consequently, it is known as _toloque_. =Lepidophyma flavimaculatum flavimaculatum= Duméril Chinajá, 8; 15 km. NW of Chinajá, 2. Individuals were found beneath logs on the forest floor or moving about in the litter on the forest floor. One was observed crawling across a trail during a heavy rain. In some adults the tan dorsal spots are large and distinct; in others the spots are small and indistinct. Two juveniles, apparently recent hatchlings, were found on June 28 and July 5. These specimens have snout-vent lengths of 29 mm. and tail lengths of 38 and 41 mm. =Eumeces schwartzei= Fischer Chinajá, 1.