Yesterday, I tried to draw a few broken seashells that I keep on my desk. I could not make the bivalve appear 3 D with shading. I titled it, "flat seashell". After seeing yours, I am going to try again. Thanks!
I don't understand the whole sand ball work of the crab either. I spent a day watching the crabs and birds at Pea Island last spring. Your drawings make me want to do some research. Thank you.