The ground cover is sparce; apparently only a few small herbs and ferns live on the heavily shaded forest floor. Important herpetological habitats include the leaf litter, rotting stumps, and rotting tree trunks on the forest floor and the buttresses of many of the gigantic trees, especially _Ceiba pentandra_ (Pl. 2). Epiphytes, especially various kinds of bromeliads, are common. Most frequently these are in the trees in the upper and middle strata.
At Toocog there is sharp break between savanna and forest (Pl. 7, fig. 2). The forest is noticeably drier and more open than at Chinajá (Pl. 9). The crowns of the trees are lower, and there is no nearly continuous canopy between 40 and 50 meters above the ground. Although _Swietenia macrophylla_ and other large trees occur, they are less common than at Chinajá. Especially common at Toocog are _Achras zapote_, _Brosimum alicastrum_, and various species of _Ficus_.
The localities from which specimens were obtained are cited below and shown on the accompanying map (Fig. 1).
[Illustration: FIG. 1. Map of El Petén, Guatemala, showing localities mentioned in text.]
Chinajá.--Lat. 16° 02´, long. 90° 13´, elev. 140 m. Camp of the Ohio Oil Company of Guatemala and formerly a small settlement. On some maps Chinajá is located just to the north of the Alta Verapaz--El Petén boundary; recent surveys place the location just to the south of the imaginary line through the rainforest. Field work was conducted in the immediate vicinity of the camp, on the lower slopes of the Serrania de Chinajá, and at several sites to the northwest and north-northwest of Chinajá, where the forest was being cleared. The entire area supports rainforest.
La Libertad.--Lat. 16° 47´, long. 90° 07´, elev., 170 m. A town on the savannas in central El Petén; although we collected there in the rainy season, the specimens obtained on the savannas are not included in this report.
Paso Subín.--Lat. 16° 38´, long. 90° 12´, elev. 90 m. A small settlement on the Río Subín, a tributary of the Río de la Pasión. Specimens were obtained in rainforest in the immediate vicinity of the settlement.
Río de la Pasión.--A large river flowing northward through southern El Petén and thence westward into the Río Usumacinta. Specimens were obtained along the river between the Río Subín and Sayaxché.