ANCIENT D WELLING $ OF THE BIO VERDE VALLEY. 745 



to the Georgia sea-islands of ante-helium fame, may be mentioned 

 as familiar examples the barriers which in Virginia and North Car- 

 olina separate Albemarle and Pamlico Sounds from the ocean ; in 

 Florida, Amelia Island on which is bnilt the city of Fernandina ; 

 Anastasia Island, in front of St. Augustine ; and the beaches which 

 separate Halifax and Indian Rivers from the Atlantic. The last- 

 named rivers are the lagoons which separate the barriers from the 

 mainland shore. Lake Worth is one of these lagoons, of which 

 the inlet has been closed. 



To what extent the Florida Keys may be included in the cate- 

 gory of barrier beaches must be decided by future investigation. 

 Key West is evidently a wave-built sand-bar composed of frag- 

 ments of coral, molluscan shells, and foraminifera, and it seems 

 likely that Cayo Largo and others of that type may be of similar 

 origin. The coquina deposits of the vicinity of St. Augustine are 

 also wave-formed. 



The hypothesis of Prof. Louis Agassiz, that the Florida Keys 

 are all of organic origin — i. e., that they were formed by the growth 

 of coral reefs — may be true so far as the determination of their 

 location and direction. A submerged reef of coral may have 

 formed a nucleus on which the waves and currents deposited a 

 load of calcareous sand, but the superficial portion is evidently 

 similar in origin to that of the beaches farther north. 



Barrier beaches are found on all the sea-coasts of the world 

 where opportunity for their growth has been afforded, and those 

 of New Jersey may be regarded as types of these formations in all 

 their essential features. 



-♦•»-♦- 



ANCIENT DWELLINGS OF THE RIO VERDE VALLEY. 



By EDGAR A. MEARNS, 



ASSISTANT SURGEON, V. S. A. 



AS an officer of the medical department of the United States 

 - Army, the writer was assigned to the military department 

 of Arizona in 1884, and took station at Fort Verde, in the central 

 part of that territory, in March. Strange were the sensations 

 that we experienced on the morning succeeding our arrival, as 

 we looked for the first time upon the broad valley of the Rio 

 Verde, hemmed in by rugged mountains on the west, and terraced 

 limestone cliffs with intervening mesas on the east. To the 

 northward Beaver Creek poured its turbid flood into the Verde, 

 whose banks were filled to overflowing by the waters sent down 

 by the melting snow upon the distant Mogollon Mountains. 

 Eighty miles to the north, beyond the ruddy cliffs of the " Red 

 Rock Country," San Francisco Peak, the highest point and most 

 prominent landmark in the territory, gleamed in snowy white- 



TOL. XXXYII. 54 



