Champotón.--Lat. 19° 21´ N, long. 90° 43´ W, sea level to five meters. A fishing village on the Gulf of Mexico. Collections were made principally at our camp five kilometers south of the town. Low deciduous forest, second growth, and _milpas_. Escárcega.--Lat. 18° 37´ N, long. 90° 44´ W, elevation 65 meters. A village in southwestern Campeche. Field work was carried out principally in the vicinity of an agricultural experiment station seven and a half kilometers west of the town. Second growth and moderately tall rainforest. Isla del Carmen.--Lat. 18° 43´ N, long. 91° 41´ W, sea level to two meters. An island in the mouth of Laguna de Términos. Collections were made at our camp on the northeastern end of the island, about one kilometer southwest of Puerto Real. Coconut plantations and mangrove swamp. Quintana Roo Felipe Carillo Puerto.--Lat. 19° 35´ N, long. 88° 02´ W, elevation 30 meters. A village in east-central Quintana Roo. Field work was centered at Rancho San Miguel, about four kilometers north-northeast of the village. Mostly second growth rainforest with scattered large patches of tall trees (to 30 meters). Several large _milpas_ were present on the ranch some of which had been recently cleared. Our camp was at a large aguada bordered on one side by an extensive marsh with tall dense grass. Isla Cozumel.--Lat. 20° 27´ N, long. 86° 26´ W, sea level to 10 meters. A large island, 15 kilometers east of the mainland. Collections were made on the northwestern part of the island from one to five kilometers north-northeast of the village of San Miguel in low, dense deciduous forest. Isla Mujeres.--Lat. 21° 12´ N, long. 86° 43´ W, sea level to 30 meters. A small, narrow island about eight kilometers from the coast at the northeastern end of the peninsula. Field work was done on the beach at the northern end of the island, in low deciduous forest in the middle of the island, and in low deciduous forest and cactus (_Opuntia_) association on a high rocky bluff on the southern end of the island. [Illustration: FIG. 1. A map of the Yucatán Peninsula of Mexico showing localities referred to in the text.] Pueblo Nuevo X-can.--Lat. 21° 52´ N, long. 87° 26´ W, elevation 10 meters. A village five kilometers east of X-can, Yucatán, in rainforest with dense underbrush. Specimens were obtained from the immediate vicinity of the village. Puerto Juárez.--Lat. 21° 10´ N, long. 86° 49´ W, sea level. A small port on the Caribbean Coast with alternating sand beach and limestone shore. Mangrove swamps extend a short distance inland at various points. Specimens were collected in rainforestlike vegetation at a small _cenote_, in low deciduous forest, and at our camp along a large, cleared airstrip four kilometers west-southwest of the village. Yucatán