1 pnocBEBmes of the geological society. 



he says, " The whole forms such an assemblage of sedimentary de- 

 posits as would probably be presented to observation if a mass of 

 the bed of the Atlantic, 2000 ft. in thickness, were elevated above 

 the waters, and became dry land ; the only essential difference 

 would be in the generic and specific characters of the imbedded 

 animal and vegetable remains." Whether viewed by naturalists or 

 by geologists, the similarity of origin seems to have occurred to both; 

 and I am not aware that the question of depth ever seriously inter- 

 fered with this view amongst geologists, who, on the contrary, 

 rather considered the mass and fossils of the chalk to be an indica- 

 tion of the possibility of Hfe at great depths. Both deposits were 

 also found to contain numerous peculiar and simple organisms, which 

 were named Coccoliths* and Coccospheres (noticed by Wallich, 

 Huxley t, and Sorby), while the profusion of the particular Forami- 

 nifer the Olohigerina, and the later discovery of siliceous Sponges, 

 are other features in common. Except by Mr. Bailey, the presence 

 of Diatoms has not been noticed %• 



Prof. Rupert Jones has kindly filled up for me the following Tables, 

 the results being based chiefly on Messrs. Parker and Jones's excel- 

 lent account of the Foraminifera from the North Atlantic and 

 Arctic oceans §. They determined 110 species as now living in 

 those seas; and of these they recognized 19 as fossil in the Chalk. 



* Mr, Carter now considers tbis to be a calcareous unicellular alga, the frus- 

 tules of which form the Coccospheres. He proposes for it the name of Melobesia 

 unicellularis. It occurs in abundance in the Laminarian zone off the Devonshire 

 coast. Another species, the M. discus, he considers peculiar to the deep Atlantic. 

 Ann. & Mag, Nat. Hist, for March 1871, 



t Prof. Huxley states that Dr. Giimbel of Vienna has now discovered these 

 bodies in all sedimentary strata. 



J Count Ab. Castracane, of Rome, however, has since examined some of the 

 mud obtained in the first ' Porcupine ' expedition at a depth of 14,610 feet, for 

 Diatoms, and reports that he discovered a rare species of Asterompkalos, which he 

 found, for the first time in Europe, in the Adi-iatic in 1863. He states also 

 that " Specimens of Hemidiscus occur in greater number, and perhaps also 

 some allied species like Euodia, of which I am not aware that, up to the pre- 

 sent time, any examples have before been found in Europe ; at least I have not 

 discovered any mention of them in the various authors I possess on the subject. 

 Besides these, the species of Diatoms most abundant in this deposit are the 

 Coseinodisci ; and of these the Coscinodlscus lineatus, Ehr,, is the most fre- 

 quently met with. There are numerous Melosirce, Bacteriastra, Triceratia, 

 Bacillarim, Pleurosigmata, Synedrcs, Naviculw" &c. Count Castracane is unable 

 to determine whether these lived at the bottom of the ocean or near the surface. 

 (Accademia Pontificia de' Nuovi Lincei, sess. del 3 Aprile 1870.) 



§ Transactions of the Eoyal Society for 1865. 



