.--The most beautiful and legendary bird of Middle America was named by Pablo de la Llave "Pharomachrus Mocinno," in honor of Jos Mariano Mocifio, an early Mexican naturalist and participant in a scientific expedition to Guatemala (Registro Trimestre, 1, no. l: 48, 1832). Until recently authors followed the original describer in spelling the specific name mocinno, with "nn" (see synonymy, Ridgway, Birds of North and Middle America, vol. 5: 738, 1911; Cory, Catalogue of Birds of the Americas, pt. 2, no. 2: 319, 1919; Dickey and van Rossera, Birds of El Salvador: 284, 1938). In 1945 Peters (Check-list of Birds of the World, vol. 5: 148) listed the specific name as "mocino," with a single "n," and (erroneously) cited de la Llave as having named the bird "Pharomachrus Mocino." Zimmer (Amer. Mus. Novit., no. 1380: 50, 1948) thonght Peters purposely emended de la Llave's name on the assumption that the Spanish letter "fi" in Mocifio's name was better translitcratcd into "n" than into "nn," and added, "I prefer to revert to De la Llave's original spelling." As Peters' spelling has been copied in influential recent works (Blake, Birds of Mexico, 1953; Miller et al., Distributional Check-list of the Birds of Mexico, Pt. 2: 11, 1957), it seems advisable to call attention to the fact that no emendation was warranted. The International Rules provide: "The original orthography of a name is to be preserved unless an error of transcription, a lapsus calami, or a typographical error is evident." De la Llave's original spelling was both intended and correct. He used the same form in a later paper (La Naturaleza, 2: 17, 1874). Latin words with "nn" generally softened in Spanish into "fi," and the "fi" sound was formerly written "nn." The tilde represents the suppressed extra "n" of the older orthography. Transliteration into Latin of the Spanish "fi" by "nn" was standard scientific usage--recommended by the A.O.U. Code of Nomenclature: 65, 1892. As de la Llave's spelling, mocinno, was in no sense an error, it should bc retalned.--E. EISE,M^NN, American Museum of Natural History, New York, N.Y.