THE FAMILY NUMMULINID^ 245 



outline of the convolutions is visible externally. 

 Eocene. 



Example. — A. exponens, Sowerby sp. {Nummu- 

 laria), ' Trans. Geol. Soc. Lond.' ser. 2, vol. v. 1834 

 (1840), p. 719, pi. Ixi. figs. 14 a-e. D'Archiac and 

 Haime, ' Descr. Anim. foss. groupe Nummulitique 

 de rinde,' vol. i. 1853, p. 148, pi. x. figs. 1-10. 



The shell of this species is discoidal and thin, 

 with a central depression more or less pronounced. 

 The surface of the test is covered, especially in the 

 central area, with fine radiating pustular or granular 

 lines. The septation of the shell is more clearly 

 seen towards the periphery. It is a wide-spread 

 form, and has been found in various Eocene de- 

 posits in Spain, France, Switzerland, Bavaria, 

 Carinthia, the Carpathians, Northern Africa, Asia 

 Minor, and in the Cashmere Mountains, upon the 

 right bank of the Biver Indus, and in the Province 

 of Cutch, in India. (Plate 14, figs. C, c.) 



Siih-faviili/ 4. Cycloclypein^. 



Test complanate with a thickened centre, or 

 lenticular ; consisting of a disc of chambers arranged 

 in concentric annuli, with a more or less lateral 

 thickening of laminated shell-substance, or of acer- 

 vuline layers of chamberlets. Septa double, and 

 furnished with a system of interseptal canals. 



Genus Cycloclijpeus, Carpentee. 



Discoidal layer usually single ; with superimposed 

 laminae of finely tubulated shell-substance, thickest 



