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On a Fossil Marine Diatomaceous Deposit from Atlantic City. N.J. 



By C. Hknry Kain and E. A. Sohultzk. 



(Plate LXXXIX). 



In sinking the second artesian well at Atlantic City, N. J., 

 there has recently been discovered a fossil diatomaceous deposit 

 of exceeding interest, not only to the student of diatoms, but to 

 the geologist as well. By comparing the species found in it with 

 those found in the famous deposits of Maryland and Virginia, a 

 striking similarity will be observed. It is not the purpose of the 

 present paper, however, to deal with the general geological re- 

 sults, especially as Mr. Lewis Woolman, the discoverer of the 

 deposit, will make a full report to the Philadelphia Academy of 

 Natural Sciences, upon the completion of the well. Mr. Wool- 

 man made a report upon the geological results observed in sink- 

 ing the first well, which was begun in 1886, but, desiring to make 

 a more accurate examination of the character of the successive 

 strata, when the second well was contemplated he made arrange- 

 ments to obtain a complete series of earth specimens. In a stratum 

 of clay which was struck at a depth of 387 feet, he discov- 



m 



ered diatoms, and, at his request, the investigation, of which this 

 is a record, was immediately undertaken with a view of deter- 

 mining the species found. 



Thus far, the diatoms have been found in a series of six clay 

 beds occurring between the depths of 387 and 6^8 feet These 

 beds are separated by layers of sand in which no diatoms occur. 

 The diatoms found in the upper stratum are few in number, gen- 

 erally small in form and much broken. At a depth of 406 feet 

 the deposit is much richer, and several interesting species not 

 found in the lower strata are fairly plentiful, such as Diniere- 

 gramuia Nova Ccesarcea^ Aidiscus spiiwsiis, and Rhabdonema At- 

 lanticmn. Triceratitan semicircidare is particularly abundant at 

 this depth, although it is also found to some extent in the deeper 

 strata. The richest portion of the deposit, however, is at a depth 

 of 550 feet Here occurs for the first time a very curious new 

 form, which we have provisionally called BiddidpJiia Brittoniana^ 

 although Prof H. L. Smith is doubtful whether it is not really a 

 new genus. A further examination of other specimens will be 



