236 Revieics — United States Geological Survey. 



II, — United States Geological Survey. Bulletin No. 268 : 

 Series C, Systematic Geology and Palteontology, Charles D. 

 Waloott, Director. Miocene Foraminipkra from the Monterey 

 Shale of California : with a few Species from the Tejon 

 Formation. By Rufus M. Bagg, jun. pp. 1-55, plates i-xi. 

 8vo. Washington, 1905. 



THE Miocene Foraminifera described in the above Bulletin were 

 collected by Professor J. C. Branner from the Monterey Shale 

 rear Asuncion Station, on the Southern Pacific Railway, in San 

 Luia Obispo County, California. 



The Monterey Shale is between 2,000 and 2,500 feet thick here, 

 and forms one broad fold with nianj^ small faults. The shale 

 contains layers that are more or less sandy and even flinty. An 

 abundance of well-preserved Foraminifera occur in the softer parts of 

 the shale, the bulk of which is made up of diatoms. The Monterey 

 Shale rests in this region upon sandstones which are referred to the 

 Chico Group ; and it is overlain by beds regarded by the author as 

 of Pliocene age, but by Dr. Fairbanks as Upper Miocene. 



The result of a study of the fossils yielded an interesting fauna 

 of sixty -six species, including a few varieties, and seventeen genera. 

 The latter comprise Bulimiiia, BoUvina, Lagena, Nodosarin, Cristel- 

 laria, Uoigeriua, Sagrina, Glohigerina, Orhnlina, PuUenia, Biscorbina, 

 Tritncatulina, Anomnlina, PulviuHiina, Rotalia, Nonionina, and 

 Polystomella. Among these it will be noted that there are no 

 arenaceous genera and species, nor warm water Miliolidse; that 

 there is only one member of the Nummulitic group, but a large 

 number of rotaline types. 



The majority of the forms represented are identical with such as 

 are abundant in the North Atlantic Ocean at the present time, and 

 the author considers that the conditions of oceanic temperature 

 and depth at which the California beds were laid down are fairly 

 represented in that sea. The fossils were probably deposited in 

 waters the depth of which was less than 500 fathoms. 



The fauna as a whole is remarkably similar to that of the older 

 Pliocene beds of Monte Bartolomeo (Lake of Garda) described by 

 Johann Egger in 1895, a fact already pointed out by Chapman 

 (1900) in his report on the California Foraminifera (Proc. California 

 Acad. Sui., ser. iii, vol. i). 



An interesting table is given showing the limits of depth of 

 •existing representatives of the fossil Foraminifera found in the 

 Miocene of California. The depths vary from shoal water to 

 upwards of 3,000 fathoms. The habitats of some species are 

 limited to special localities; others have a worldwide oceanic 

 distribution. 



The table is followed by a list of the described species, 

 systematically arranged, after which comes a bibliography in 

 which many well-known works are enumerated; finall}^ the 

 descriptions of the species, and a full index. A. H. F. 



