40 



After a preliminary examination, we find them to contain, 

 among others, the following fossil Diatomaceous Plants, viz : 

 Heliopelta Metii, Ehr. 

 Heliopelta Leeuwenhoekii, Ehr. 

 Heliopelta Euleri, Ehr. 

 Heliopelta Selligueii, Ehr. 

 Pyxidicula opercnlata, Ehr. 

 Pinnularia Couperii, Bailey. 

 Coscinodiscus gigas, Ehr. 

 Coscinodiscus radiatus. 

 Coscinodiscus oculus iridis, Ehr. 

 Gallionella sulcata, Ehr. 

 Actinocyclus undulatus, (Senarius, Ehr.) 

 Navicula Bombas, Ehr. 

 Navicula striatufa, var. 

 Craspedodiscus elegans, Ehr. 

 Zygoceros rhombus. 

 Sceptroneis caduceus, Ehr. 

 Podiscus Rogersi, Bailey. 

 Terceratium favus. 

 Pictyocha fibula. 



The variety of earth from just above Nottingham is cleaner 

 and appears to have more specimens of Heliopelta than that 

 just below. 



We agree with Doct. Johnstone in believing the Notting- 

 ham earth to be the same as Bermuda Tripoli ; at least we 

 are now certain of another locality of the Heliopelta, hereto- 

 fore^considered so rare. A communication by Dr. Johnstone, 

 arguing this point, was read at a meeting of the American 

 Scientific Association recently in session at Newport. 



In the year 1844, Prof. Bailey received from M. Tuomey 

 Esq., of Petersburg, Ya., a fine specimen of infusorial earth, 

 labelled " Tripoli from Bermuda." Mr. Tuomey received 

 it from some mineralogical correspondent, and had no doubt 

 that it came from the Bermuda Islands. Collectors have sought 

 in vain for it at those islands, and Bermuda as its locality 

 has long since been given up. ' The Heliopelta and its vari- 

 eties are abundant in Bermuda Tripoli and have not yet 

 been noticed in any other earth, except the present Notting- 

 ham specimens. From this only specimen received by Prof. 



