Although this celebrated work relates mainly to the neighbouring State of Paraguay, so many birds are common to Paraguay and La Plata that it has of course a most important bearing on the Ornithology of the latter country. Azara, unfortunately, gave only Spanish names to his birds, so that the Latin titles of them are mostly those of Vieillot, who translated Azara's remarks and gave scientific names to his birds in different volumes of the 'Nouveau Dictionnaire d'Histoire Naturelle' (Paris, 1816-19). A most useful Index to Azara's 'Apuntamientos' was published in 1847 by Dr. G. Hartlaub of Bremen[11]. A more modern _résumé_ of the Birds of Paraguay, in which much information is contained, has been recently written by Hans, Graf v. Berlepsch[12]. [11] Systematischer Index zu Don Felix de Azara's Apuntamientos para la historia natural de los páxaros del Paraguay y Rio de la Plata. Bremen, 1847. [12] Journ. f. Orn. 1887, p. 1. BARROWS, WALTER B. Birds of the Lower Uruguay. Bulletin of the Nuttall Ornithological Club, vol. viii. pp. 82, 128, 198; and The Auk, 1884, pp. 20, 109, 270, and 313. This excellent observer was resident at Concepcion del Uruguay in 1879 and 1880, and afterwards made an excursion from Buenos Ayres southwards to the Sierra de la Ventana. His notes, many of which are incorporated in the present work, relate to about 200 species. BURMEISTER, Dr. HERMANN. (1) Reise durch die La Plata-Staaten, mit besonderer Rücksicht auf die physische Beschaffenheit und den Culturzustand der Argentinischen Republik. Ausgeführt in den Jahren 1857, 1858, 1859, und 1860. 2 vols. Halle, 1861. In a work on Argentine Ornithology it is hardly necessary to explain who Dr. Burmeister is. The Director of the Museo Publico is as well known in Europe as he is in Buenos Ayres. It should, however, be here mentioned that in the second volume of 'Reise durch die La Plata-Staaten' Dr. Burmeister has given an excellent systematic synopsis of the Vertebrate Animals of the Argentine Republic. Of the class of Birds 263 species are enumerated as having been met with within the limits of the Republic up to that date, and references, native names, and general observations as to habits and localities are attached to each species. This is in fact up to the present time the best, or, we might say, the only authority on the Birds of the Argentine Republic. Besides this, Dr. Burmeister has published several other contributions towards our knowledge of Argentine Ornithology, namely:-- (2) Sobre los Picaflores descriptos por D. Felix de Azara. Por Dr. German Burmeister. An. d. Mus. Publ. d. Buenos Aires, tomo i. p. 67 (1864). [An essay on the eleven species of Trochilidæ, described by Azara, which appear reducible to six.] (3) Extract from a letter addressed to Mr. Sclater on the _Tyrannidæ_ found near Buenos Ayres. P. Z. S. 1868, p. 2. [Contains a list of 10 species of this family.]