299 Tertiary Foraminifera 5 



In the Journal of the New York Microscopical Society for 

 April 18M7, Mr. Anthony Woodward gives a list of species 

 which he identified in some Miocene sand enclosed in a Pec- 

 timculus shell from Petersburg, Virginia. This shell had lain 

 undisturbed for many years and when examined yielded twen- 

 ty-one different species of Foraininifera. The following year 

 in Otto Meyer's Report* upon Upper Tertiary Invertebrates 

 from the west side of Chesapeake bay, Mr. Woodward ment- 

 ions three species; Miliolina seininnlum (Linne), Gaiidryina 

 pupoides d'Orbigny, and Polymorphina compressa d'Orbigny. 

 The latter I found to be very abundant and wide-spread, oc- 

 curring in many localities and it is present in both Eocene and 

 Miocene deposits. 



In the reports upon the artesian well borings of New Jersey 

 made during the last few years Mr. Lewis Woolman of Phila- 

 delphia has recognized the presence of Foraminifera many times 

 but so far as I am aware he has not determined the various 

 species observed. It is probable that these samples from the 

 well borings will furnish a number of species when system- 

 atically studied, especially those of the Miocene age. 



This seems to be all that has been done upon the Foramin- 

 ifera of the Middle Atlantic Slope up to the present time. 

 Nearly all species previously recognised have been identified by 

 the writer and many forms are here described for the first time 

 from the Atlantic Slope Tertiary. Two forms are believed to 

 be new. One, Spirillina orbicularis, is from the Miocene beds 

 of Yorktown, Virginia; the other, Spiropleda darki, is from 

 the Eocene of Woodstock, Virginia. Until the discovery of the 

 genus Spiropleda by the author in the Virginia Eocene this 

 was , unknown in deposits of Tertiary age although it was 

 known in the Cretaceous and is found in existing oceans. 



ElTHOLOGICAL CHARACTER OF THE DEPOSITS. 



The mineral glauconite plays an important part in the Eo- 

 cene formation of the Middle Atlantic Slope and in some lo- 

 calities constitutes almost the entire bed. This greensand is 

 often argillaceous and constitutes with the shell material pres- 

 ent a true marl, which in many places is so indurated as to 

 form limestone bands. This feature is well illustrated on the 

 Potomac river at the mouth of Aquia creek, Virginia where 



*Proc. Acad. Nat. Sci. Phila., 1888, pp. 170-171. 



