540 abstracts: ornithology 



ciable error is made by expressing the total carbon dioxide found as a 

 mixture of carbonate and bicarbonate. 



R. W. Stone. 



GEOLOGY. — Deposits of Claiborne and Jackson age in Georgia. C. 

 W. Cooke and H. K. Shearer. U. S. Geol. Survey Prof. Paper 

 120-C. Pp. 41, with geologic map and figures. 1918. 



Intensive field work, supplemented by critical study of the fossils, 

 has resulted in the following changes in the interpretation of the strati- 

 graphy of the Eocene of the Coastal Plain of Georgia: 



The deposits of Claiborne age, which had been thought to extend 

 uninterruptedly across the entire width of the State, are restricted to 

 two areas, an eastern area, along Savannah River and McBean Creek, 

 and a western area, between Flint and Chattahoochee Rivers. For 

 the deposits in the eastern area, the name McBean formation is re- 

 tained ; the deposits in the western area are designated Undifferentiated 

 Claiborne. In the intermediate region, the Claiborne beds are over- 

 lapped by deposits of Jackson age. 



The deposits of Jackson age include the Barnwell formation, which 

 is not of upper Claiborne age as Vaughan was led to believe by a pre- 

 liminary study of the fossils, and the Ocala limestone, which earlier 

 writers referred to the Vicksburg group. These two formations appear 

 to have been formed at least in part contemporaneously, but differ in 

 lithologic and faunal characters. The Twiggs clay member of the 

 Barnwell formation includes the so-called "Congaree clay member of 

 the McBean formation" and certain clays that were considered a part 

 of the Jackson formation by previous writers. The name Tivola 

 tongue is proposed for a wedge of bryozoan-bearing limestone that 

 projects from the lower part of the Ocala limestone into the Barnwell 

 formation. 



An interesting by-product of this investigation is the discovery in 

 the Barnwell formation of a moUuscan fauna not previously known to 

 occur east of Arkansas. 



C. W. C. 



ORNITHOLOGY. — A Criticisrn of two recent lists of I'owa birds. Ira 



N. Gabrielson. Wilson Bull. 29 : 97-100. 1917. 



Some recent Iowa records of 16 species of birds are here shown to be 



certainly or probably erroneous. Among these are three species, 



Branta nigricans, Hierofalco mexicanus, and Cnjptoglaux funerea rich- 



