174 THE AMERICAN MONTHLY [June 



deposit, requesting him to visit it and send me a quanti- 

 ty of the deposit. Through his kindness I secured some 

 fifty pounds of clay, and after the receipt of the fossil 

 clay I was enabled to make a study of the deposit. 



After preparing and examining the equivalent of about 

 fifty slides, I became suflBciently acquainted with the 

 chief characters of the deposit, to enable me to make 

 some comparative deductions with reference to the two 

 principal sources of North American marine fossil depos- 

 its. These are generally known and familiar to Ameri- 

 can and foreign microscopists. Such deposits are 

 known as occurring at Monterey, Cal. and at other sites 

 on the Pacific Coast. The deposits on the Atlantic Coast 

 are found at Nottingham, Md, Richmond and Petersburg 

 Va.,and at other points from New Jersey to South Caro- 

 lina. 



As a result of the studies made from a relatively small 

 quantity of the deposit, not amounting to more than a 

 few ounces in the aggregate, I have been enabled to note 

 and tabulate species represented by the following gen- 

 era : Amphora, 5; Amphiprora, 4; Auliscus, 3; Aula- 

 codiscus, 3 ; Actinocyclus, 3; Actinoptychus, 6; Aster- 

 olampra, 2; Amphitetras, 2; Biddulphia, 6; Coscino- 

 discus, 10; Craspedodiscus, 2; Cocconeis, 1; Cyclotella, 

 2; Corinna, 2; Diatoma, 2; Dimeragramma, 1; Diplo- 

 neis, 3 ; Eunotogramma, 1 ; Glyphodiscus, 2; Hyalodis- 

 cus, 2; Hemiaulus, 2; Melosira, 5; Navicula, 10; 

 Pleurosigma, 3 ; Pyscilla, 2 ; Pseudoauliscus, 1 ; Ruti- 

 laria, 1; Raphoneis, 2; Synedra, 1; Triceratum, 6; 

 Trinacria, 2 ; — approximating one hundred species in 

 the aggregate. Associated with the diatoms are addi- 

 tional fossil organic remains viz. some 20 species of For- 

 aminifera, 6 or more of Radiolarians, various sponge and 

 gorgonia spicules, minute spines of echinoderms ; stellate 

 spicules, zanthidian spheres, and coccoliths of the chalk 

 resembling those of the recent sea bottom ; also crystals 



