136 HALKYARD, Fossil Foramimfera of the Blue Marl 

 First Scheme. 



NUMMULITES ELEGANS, Sowerby, (1829.) 



Nummulites elegans (B) planulata, Lamarck. 1804. 



Second Scheme. 

 Nummulites (B) planulata, Lamarck, 1804. 

 Nummulites, planulata, Lamarck, (A) elegans. 

 Sowerby, 1829. 



The species of Nummulites in which the two forms have 

 been recognised may up to the present amount to some twenty 

 or twenty-five. 



In the soft Maris of the Cote des Basques, the genus is 

 comparatively rare, and the specimens found are not in sufficient 

 number to allow of any estimate being made as to the relative 

 proportions of the forms A and B. Nummulites are, however, 

 very plentiful in the sands overlying the Marls and also appear 

 again in considerable quantities in the hard limestones at the 

 base of the Marls. These facts seem to show that a muddy 

 sea bottom does not provide a suitable habitat for the genus, 

 or else that soft Marl, which is liable to extremes of dryness 

 and moisture, is not conducive to the preservation of its fossil 

 remains. 



De la Harpe records six Nummulites from the Cote des 

 Basques of which four fall into two "couples" and are 

 bracketed as such. 



(Nummulites contorta, Deshayes. 

 \ Nummulites striata, d Orbigny. 

 / Nummulites guetiardi, d'Archiac. 

 \ Nummulites biarritzensis , d'Archiac. 

 Nummulites variolaria, Sowerby. 

 Nummulites lucasana, Defrance. 



Of the above I have only found four forms, but I have been 

 fortunate enough to add others to the list. 



330. 2 — Nummltlites irregularis, Deshayes. 

 330A. 1 — Nummulites sub-irregularis, de la Harpe. 



Nummulites irregularis, Deshayes, 1S38, Mem. Soc Geol. 



France, [1], vol. Ill, p. 67, pi. V, figs. 15-16. 

 N. irregularis, de la Harpe, 1883, Mem." Soc. paleont. Suisse, 



vol. X, p. 154, pi. IV, figs. 16-34; and pi. V, tigs. 1-2. 

 l—N. sub-irregularis, de la Harpe, 1883, Mem. Soc. paleont, 



Suisse, vol. X, p. 158, pi. V, 3-14. 



