all of the Comissao Mixta, are also acknowledged with pleasure.Specimens were contributed by several individuals, in particular by Madre Esther Bottega of the Colegio "Santa Clara" of San Jose de Chiquitos, and by Sr. Orivaldo Oliveira Nogueira of El Porton.The lizards were identified by Dr. P. E. Vanzolini. Since circumstances prevented Mr. W. C. A. Bokermann from completing the identification of the frogs, the collection was reviewed by Mr. Benjamin Shreve of the Museum of Comparative Zoology. The latter also reviewed certain doubtful identifications of snakes made by me. I certainly appreciate having had the benefit of his wide knowledge of South American reptiles and amphibians.