Prince Maximilian of Wied made important collections of reptiles and other vertebrate animals during pioneering expeditions to Brazil and North America. These were purchased for the American Museum in 1869. The present paper emphasizes Brazilian materials collected in 1815–1817.

Prince Maximilian (aka Wied, Neuwied, and Prince Max) published extensively on this collection, especially in the Beiträge zur Naturgeschichte von Brasilien (“Contributions to the natural history of Brazil, 1825–1833”)—a meticulous account of the species collected—and in Abbildungen zur Naturgeschichte Brasiliens (“Illustrations of the natural history of Brazil, 1822–1832”).

The unnumbered folio plates of the Abbildungen are so important, and so difficult to access, that the herpetological ones are resized and reprinted herein. These hand-colored plates are rare (only 300 of each were produced) and are reproduced herein “as is” with arbitrary plate numbers 1–56; this numbering approximates the organization of the present work and also the order of species presentation in volume 1 of the Beiträge.

When received at AMNH, the herpetological specimens were accompanied by the Prince’s handwritten manuscript list, dated 1860, with 441 numbered items. The list is not a specimen catalog but a useful index to the collection, as indicated by its title: Verzeichniss der Reptilien-Sammlung nach Duméril, Bibron, und Jan. It includes separately numbered lists of genera and of species in the collections and therefore corresponds to taxa, not to actual specimens.

Wied did not designate types, a concept not yet established; Wied, types, like Linnaean types, must be identified retrospectively. Our objective has been to identify the surviving types of Brazilian reptiles and amphibians in the Maximilian collection. Our starting point was forcibly the Beiträge, a work of singularly modern conformation. It may contain for each species a synonymy, a description, measurements, meristic data, and a discussion of distribution.

The criteria for decision on the identification of types were fourfold: the description, the measurements, the scale counts, and the Abbildungen plates. A total of 21 primary type specimens were thus identified in the Wied collection (including some originally identified as types or cotypes). These include 15 holotypes (mostly newly identified) and six lectotypes (mostly newly designated).

However, Wied had named about 61 species from his Brazilian collection, so approximately 40 primary type specimens of reptiles and amphibians are missing. Most of these never reached the American Museum; many had disappeared in Europe before Maximilian had started writing his 1860 manuscript catalogue. Wied wrote that he had been unable to preserve several specimens; some of the others may be in European museums or possibly in the remaining collection of his friend Blasius Merrem at the University of Marburg.