30 
One fifth of the margin of our shell shows the diagonal 
striae, nearer approaching those of the common circles re- 
ceding from the hinge. T. Falula continues the same 
throughout. Both shells are diagonally striated in ours, 
and only one shell in T. Falula j the other being remark- 
ably smooth and polished, with but few of the common 
concentric striae. Our shell is rather yellower. Both 
require a magnifier to see the striae distinctly, and then 
often show prismatic hues of a pearly nature. 
