Need info. on the structure of fish scales

[Tom Worcester]

I was wondering if anyone knows how the circuli (ie. rings) on a fish 
scale are actually formed. I have been told that a scale looks like a 
pyramid when viewed sideways (ie. the rings are like a stack of pancakes 
with the largest "cake" on the bottom). I think it looks like a record 
with ridges. Any ideas??? Also any ideas of any other newsgroups that 
might be more appropriate for this? Thanks!!!