510 Prof. T. B. Jones and W. K. Parker — On Foramimfera. 



small individuals of Planorbulina ammonoides. 53. B. picta ? This is 

 Puhinulina Micheliniana, D'Orb. sp., seen from its flat (upper) spiral 

 face. The same species is represented in pi. xxvii., fig. 52, by a 

 rather larger specimen {" Planulina picta") from the Chalk of 

 Meudon, viewed through the vertical thickness of the shell from its 

 high umbilical (lower) face. This belongs to a large family of 

 Eotaline Foramiuifera, which group themselves around Pidvinulina 

 repanda, Fichtel and Moll, sp. It belongs more especially to the 

 subgroup of which P. Menardii is the type. This attains its best 

 growth at about 100 fathoms in the existing seas, but lives well at 

 abyssal depths, even at more than two miles depth ; whilst, on the 

 contrary, in shallow water it degenerates into bizarre varieties. 

 D'Orbigny's Botalia crassa, figured on the same plate (Mem. Soc. 

 Geol Fr., iv. pi. 3, f. 7, 8), is also a variety of Puhinulina Menardii. 

 These are found in existing seas under the conditions mentioned 

 above, and are abundant in the Gault, Chalk-marl, and Chalk. 



The other objects from the Chalk shown in this interesting plate 

 are some siliceous and calcareous Sponge Spicula, some Morpholites, 

 including Coccoliths, possibly a variety of Cyatholith without its 

 centrum, and two Diatoms, Fragilaria rliahdosoma, 1838, and Fr. 

 pinnata, 1844 (Fr. striolata, 1838). 



According to our views, as explained above, and in our papers on 

 the Nomenclature of the Foraminifera in the Ann. Nat. Hist., and 

 in other memoirs, we regard Dr. Ehrenberg's figures of the Forami- 

 nifera from the Chalk of Gravesend as referable to — 



Hodosaria omcula, D'Orb. Grammostotnum petmatula, Batscli sp. 



Vaginulina Icevigata Roemer. Virgulina Schreibersii, D'Orb. 



longa, Cornuel sp. Hemprichii, Ehr. sp. 



Textilaria striata, Ebr. Polymorphina Thouini, D'Orb. 



gibbosa, D'Orb. Globigerina cretacea, D'Orb. 



agglutinans, D'Orb. Gristellaria cultrata, Montfort sp. 



Seterostomella aculeata, Ehr. sp. Planorbulina ammonoides, Reuss sp. 



Verneuilina triquetra, Munster sp. Puhinulina Micheliniana, D'Orb. sp. 



Those of Ehrenberg's species that are mentioned in Morris's "Cat. 

 Brit. Foss.," second edition, are : — 



1. Planulina (? Gristellaria) turgida =: Gristellaria cultrata, small 

 (PI. omphalolepta, 1854). 2. Bosalina globularis = Gr. cultrata, 

 feeble (PL hexas, 1854). 3. Botalia globidosa= Globigerina cretacea. 

 4. Botalia ornata = ? Not figured in 1838, nor in 1854. 5. Botalia 

 perforata = Globigerina cretacea. 6. Textilaria aciculnta = ? Not 

 figured in 1854 : the figure given in 1838 is like that of a small 

 Virgidina. 7. Textilaria aspera-=^T. gibbosa (T. ampliata, 1854). 

 8. T. globulosa = T. gibbosa, small. 9. T. perforata (= T. gibbosa) 

 should not have been inserted, as Ehrenberg does not refer to it as 

 occurring in the English Chalk. 



It will add to the interest of these notes on Cretaceous Forami- 

 nifera, if we allude to PL xxvii. of the "Mikrogeologie," illusti-ating 

 the species and varieties that Dr. Ehrenberg discovered in the Chalk 

 of Meudon, France. These are similarly treated, and are also re- 

 ferred to in the same papers in the Journal and Transactions of the 



