C 41 3 
F I G. LI. 
Volutions fourj not joined to each other. 
Free Stone, 
F V I G. LIL 
Number of volutions uncertain, all I have 
met with being imperfeft: fpires marked with 
feveral fmall ridges: large ft volution an inch 
and half broad. Free Stone, 
FIG. LIIL 
Oval: volutions four, fmooth. * 
The figure is fomething larger than the foffil. 
Free Stone. 
FIG. LIV. 
Taper: five volutions, which are diftant 
from each other. From Fig. 48. to Fig. 54. 
inclufive are called by the quarry-men Screws, 
Found in a free-ftone quarry. 
FIG, 
