242 



and regularly crenato-sulcate, as are their interstices, 

 being marked with concentric grooves and ridges : end 

 of the last cell semilunar, narrow, convex. 0,02. 

 Aberdeen. 



P. NAUTILINA. Macg. Aberd. p. 317. Nauti- 

 liform, with the cells somewhat convex, the margin 

 rounded, the cells of the last whorl about ten or twelve, 

 little convex, narrow smooth glossy but granulated 

 towards the umbilicus which is small, the interstices 

 depressed, curved and somewhat striated : end of the 

 last cell large, cordate, nearly flat, with two series of 

 pores. 0,02. Not rare at Aberdeen. 



GENUS. NUMMULINA. 



Discoid, suborbicular, depressed, with a multilocular 

 spire, with complex walls, and arranged in the same 

 plane ; the two surfaces convex, the margin plain. 



N. MARGINATA. Macg. Aberd. p. 34. RENOIDEA 

 M. Brown. III. Con. t. 1. /. 25. Suborbicular, de- 

 pressed, glossy, convex on one side, conico-convex on 

 the other ; yellowish white, with a very thin broad 

 margin separated by a circular groove from the body 

 of the shell ; the internal spiral tube with few volutions 

 0,02. Aberdeen. Some individuals are perfectly 

 orbicular, others less so, some with a slight angle. 



