30I Tertiary Foraminifera 7 



lithologic chara(5ler. In New Jersey the lower portion of this 

 formation overlying the marl beds consists of a black micace- 

 ous sandy clay often rich in organic matter and is commonly 

 termed "rotten-stone." Near the base of the formation glau- 

 conite occurs more or less sparingly dispersed owing to the 

 transgression of the Miocene sea upon the marl beds. Where 

 the Eocene is absent the writer has found this sandy clay fill- 

 ed with casts of small Panopseas and other Miocene shells direct- 

 ly above the Lime-sands of the Rancocas formation. A good 

 iUustration of this is seen in the bank by the mill-pond at 

 Harrisonville, Gloucester county, New Jersey. 



Overlying this dark sandy clay are fine micaceous sands 

 pinkish or yellowish in color, the charadler of which is best 

 described by the words, fluffy or mealy. In some places this 

 sand carries erough argillaceous material to serve as a mould- 

 ing sand and is so used by Mr. Wilson who ships it to Phila- 

 delphia from his pits not far from Harrisonville. The famous 

 glass sands of New Jersey belong to this period. In some 

 cases the sand has become consolidated so completeh' as to form 

 a veritable quirtzite as is seen in the p^ts of Gilbert A. Ayre 

 near Marlboro, Cumberland county, N. J. The marl beds so 

 largel}- worked in Cumberland county while exceedingly rich in 

 MoUusca seem to be without Foraminifera, at least the author 

 has found none in the material examined. That they are pres- 

 ent in many of the Miocene clays has been proven by the well- 

 borings. 



In Maryland and Virginia the Miocene has a wide represen- 

 tation and consists of clays, sands, and shell marl. The clays 

 are often developed in lenticular bands as is seen in the bluffs by 

 Yorktown. This clay in that vicinity yields a number of For- 

 aminifera belonging to the Miliolid(B which indicate a warm 

 climate. The great thickness of Infusorial earth developed in 

 Maryland and Virginia must be mentioned although the fos- 

 sils found in it belong to other microscopic groups. 



The Pleistocene Foraminifera from Cornfield Harbor, Mary- 

 land, occur in a deposit of shell marl not unlike that which 

 charadlerizes the Miocene. There are a large number of forms 

 present in this deposit but they are limited to four or five genera 

 of which the genus Polystomella plays the most important part. 

 That the deposits were formed in shallow water throughout the 

 Tertiary period seems abundantly proven by the great abund- 



