84 Barrows 07t Birds of the Loiver Uruguay. [April 



unless an unusually dry season makes their abode convenient 

 grazing ground for herds of cattle, or an unusually wet one brings 

 all flesh into competition along the edge of hard ground, often 

 several miles back from the river margin. 



The river itself varies in width from half a mile in a few places 

 to five times that distance in others, while in time of flood 

 ("creciente") it oversteps all bounds and claims the whole valley 

 from blufli" to blufl'. 



Owing to the mildness of the winter comparatively few birds 

 seemed to be really migratory at this place, and from the irregu- 

 larity of the observations made during the spring, and the fact 

 that only one entire spring was spent at Concepcion, the dates of 

 arrival in most cases can be only approximately inferred. 



The few brief visits which were made to large tracts of heavy 

 woods showed that undoubtedly many other species than those 

 actually obtained might have been found there at different seasons 

 or under moi'e favorable circumstances. This is certainly true 

 with regard to birds of prey, several species of which were not 

 met with at all outside of these tracts, though abundant there, 

 while still others were not taken at all, though known to abound 

 in other parts of the province. Another season in the same local- 

 ity would doubtless yield many other species, yet probabl}' not 

 many which are i'egularly to be found in any considerable num- 

 bers were overlooked. 



Late in January, 1881, the writer became one of a party dele- 

 gated by the Argentine Government to make a provisional exam- 

 ination of the fauna and flora of the Pampean Sierras in the 

 extreme southern parts of the province of Bufenos Aires, — a 

 region but imperfectly known, and at that time only i^ecently 

 vacated by hostile Indians. Although about ten weeks were 

 spent in this work less than half was of any real value, owing to 

 the lateness of the season, the imperfect organization of the party, 

 etc. The party went by rail on January 25 from Buenos Aires 

 to Azul — over 200 miles south-west; thence forward 250 miles 

 by diligence to Bahia Blanca on the coast in latitude 38^ degrees 

 south, this being the southernmost point reached. From this 

 place the course was north 50 miles by saddle and wagon to the 

 Sierra de la Ventana (Windowed Sierra) and then westward 75 

 or 100 miles along the base of these movmtains and the Sierra de 

 Currumalan to the military posts of Puan and Carhu^, at which 



