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. Navutitina. 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. 
Grenus.—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. Marernata. Macg. Aberd. p. 34.—RENOIDEA 
M. Brown. Ili. Con. t. 1. f. 25.—Suborbicular, de- 
pressed. glossy, convex on one side, conico-cunvex 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. 
