First the answers to yesterday's puzzlers: #159 was indeed a belt buckle (although someone thought it was a fastener for an ace bandage, and I can definitely see that!), specifically my Grandmother's, made from an abalone shell in the 1920s. #160 wasn't actually a Rapidograph, which two people guessed, but that's not too far off It's a small ivory dip pen inlaid with gold filigree designs. The nib, which was evidently very small, is missing.
# 161 is a kind of milagro or holy medal as two people guessed, made from a flat but slightly curling piece of tin. I bought it in Rome from a religious article shop near St. Peter's, where it was sold as a Sacred Heart ex voto, similar to a milagro, and was meant to hang near a saint's statue in petition or thanksgiving for a prayer that was answered.
As several of you guessed, #162 is a bell, a goat bell that we found in our garden when we digging it many years ago. Mary correctly guessed #163 as a porcupine quill. I found it along a road in Italy.
The biggest mystery turned out to be #164, which I clearly didn't do a very good job of drawing!. Everyone thought it was either a loofa or some other kind of sponge. In retrospect I think it looks like the end of a whole wheat baguette. But actually it's a very large crinoid that I found in a creek bed in southern Indiana. A crinoid is a petrified blossom from prehistoric times. This is the largest one I've ever found, and it has an interesting petal-like form running down its tapering side. I should have used watercolor to draw it as the pen texture is misleading.
Well done all of you! I'll do another contest when I find some more mystery things.
And now briefly, today's drawings: up on the top, left, is an interesting straw paper that I saw in a Thai restaurant today. I carefully deconstructed it to figure out how it was made. All the other drawings are labeled-- various brushes that I use in my studio and which I find very beautiful as well as functional.