.--In the Proceedings of the Zoological Society of London for 1890 (p. 403) Sclater described a new toucan from "Upper Amazonia" under the name Pteroglossus didymus. This was based on a single specimen, obviously allied to Pteroglossus viridis humboldti. In the 67 years since its description this bird has remained unique and its status has been impossible to determine. Thus, Peters (1948: 77) writes of it, "...range unknown," but gives the distribution of humboldti as southeastern Colombia, eastern Ecuador, north- eastern Peru, and adjacent parts of western Brazil to Rio Solimes and Rio Madeira, south to northern Bolivia. Griscom and Greenway (1941: 198) record nominate viridis from several localities in lower Amazonia (Marac, Obidos, Rio JamundO) and write that it is replaced by didymus in, "...far upper Amazonia. This race and humboldti bridge the gap between viridis and inscriptus." Pinto (1938: 332-333) lists inscriptus, humboldti, and viridis, but does not mention didymus as a Brazilian bird. Gyldenstolpe (1945: 115-116, and 1951: 120) makes no mention of didymus either, although listing humboldti from a number of Amazonian localities. Meyer de Schauensee (1949: 623-624) lists humboldti, but not didymus, from extreme southern Colombia. Snethlage (1914: 226) and Cory (1919: 373) list didymus merely from the upper Amazon valley of eastern Peru. To complete this survey, it may be mentioned that Brabourne and Chubb (1912: 159) list both didymus and humboldti from eastern Peru, the former undoubtedly solely on the basis of the type specimen. Recently I was called to examine and identify some birds received alive from Leticia, extreme southern Colombia, by Mr. Lowry Riggs, a dealer of Rockville, Maryland. Leticia is on the north bank of the Amazon close to Tabatinga, Brazil, and is just across the river from Peruvian territory. This is the same area where Riggs' collector, in an earlier shipment, obtained the long lost Colombian Red-eyed Cowbird, Tangavius armenti. Among other birds in the present shipment, which included the seldom procured Selenidera reinwardtii, was a toucan which fitted the description and the colored plate (Cat. Birds Brit. Mus., vol. 19, 1891, pl. 6) of didymus. This bird, since purchased for exhibition in the New York Zoological Park, appears to be the first example of this supposed form since the hitherto unique type specimen taken not later than 1890. The chief character by which didymus differs from humboldti and inscriptus is the absence of black transverse markings along the maxillary tomium, these marks being well developed in the latter two forms. The live bird has the maxilla less extensively dear olive yellow below the dusky culminal stripe than in Sclater's figure of his type, and largely dark brown to blackish somewhat streaked lengthwise, but with a sizeable dear yellowish area occupying its middle third or more. It is more llke didymus than any other described toucan, and is identified as such without question. In plumage the two are alike, and it may be that the bill difference is due to the type being a fully adult bird and the present example not quite so mature. Several months after the bird went to the New York Zoological Park, Mr. L. S. Crandall wrote me that the bird was changing and becoming more like the published plate, and like humboldti, thereby corroborating the assumption of its being imma- ture. To quote from his letter," . . little by little the color of the bill has changed, so that while the mandible is still black, the maxilla is clear, with a black culminal stripe and a slight dark area toward the tip. The notches along the tomia were dark a month ago but now the markings are creeping upward, forming small trans- verse streaks." Mr. Riggs' collector probably acquires his birds for shipment from the Indians over a fairly considerable area in the neighborhood of Leticia, so it is not possible to pin down the locality of capture of this toucan more exactly than to call it the "Leticia area," which would include extreme southern Colombia, extreme eastern Peru, and the adjacent areas of Brazil. However, humboldti has been reported from Loretoyacu, Colombia, about 80 kilometers northwest of Leticia, and even as far north as Meta, nearly 4 ø N. latitude. It has, thus, been recorded to the north, south, east, and west of Letida, and it can only be assumed that the range of humboldti probably includes that of the so-called didyus. This makes one wonder if the latter is really anything more than an occasional aberrant humboldli, which is what I strongly suspect. If not, then didyus would probably have to be considered a dis- tinct species sympatric with, and exceedingly similar in size and in plumage coloration to Pteroglossus viridis humboldti. This is certainly much less likely than the former disposition of the case. Until evidence to the contrary is produced, the known facts hardly justify continuing to give didymus standing as a distinct form. It is apparently only an aberrant, occasional variant of Pteroglossus viridis humboldti. I am indebted to Mr. Lee S. Crandall for making a further examination of the toucan after its arrival in the New York Zoological Park and corroborating my identification of the bird with the description and published colored plate of didymus. This note is published by permission of the Secretary of the Smithson[an Institution. LITERATURE CITED BRABOUNE, LORD, AND C. CrumB. 1912. The birds of South America. Vol. 1. 504 pp. CORY, C.B. 1919. Catalogue of birds of the Americas... Field Mus. Nat. Hist., Zool. Ser. 13, pt. 2, no. 2: 317-607. GRISCOt, L. AND J. C. GmENWAY. 1941. The birds of Lower Amazonia. Bull. Mus. Comp. Zool., 88: 83-844. GYLDESSTOLrE, N. 1945. The bird fauna of Rio Jurua western Brazil. Kungl. Svens. Vetenskapakad. Handlngr., ser. 3, vol. 22, no. 3: 1-338. GYLDESSTOLrE, N. 1951. The ornithology of the Rio Purfis region in western Brazil. Ark. for Zool., ser. 2, vol. 2, no. 1: 1-320. MEYER DE SciJEsEE, R. 1949. The birds of the Republic of Colombia, pt. 3. Caldasia, vol. 5, no. 23: 381-644. PETERs, J.L. 1948. Check-list of birds of the world. Vol. 6, 259 pp. PINTO, O. M. DE O. 1938. Cat/dogo das aves do Brasil. Pt. 1., Rev. Mus. Paul., 22: 1-566. SNBTm,AOB, E. 1914. Cat/logo das aves Amazonleas. Bol. Mus. Goeldi, 8: 1-530. --HERBERT iIDMANN, U. S. National Museum, Washington, D.C.