Wow- thanks, everyone! Here's a very rough outline of what I did. I made this hat about six months ago, but I will try to look at the rounds and figure out what those stitches were. Unless noted, all yarn was worsted-weight, basic scrap (Red Heart or similar acrylic), using an H hook, and with US terms:
Round 1, dull white, from the book Better Homes and Gardens Crocheting & Knitting copyright 1977, was trying to make the cover afghan, specifically the square pictured at the very bottom left corner.
Round 2 and 3, light green, from same book (makes the star shape)
Round 4, dark turquoise blue, from same book- this is the round where I missed the chain stitches in between the shells. What a great oops!
Round 5, noticed my error, picked up some light yellow yarn and made some shells (hdc up to dc and back)
Round 6, dark red wool yarn, single crochets and spike stitches into the hdc of Rnd 5
Round 7, khaki/tan, row of single crochet
Round 8, same yarn, another row of sc
Round 9, same yarn, hdc shells of some type () looks like I did three in one stitch, skipped one stitch, then three more in next sc
Round 10, bright lavender, looks like dc into back loops only (so that a ridge is formed on the outside of the hat)
Round 11, mustard yellow wool yarn, hdc with the occasional spike stitch into Round 8/9
Round 12, same yarn, hdc row
Round 13, dark brown wool yarn, shells in sets of 5, hdc up to triple crochet
Round 14, pea soup green wool yarn (darker than Rnd 2's green), same shells as previous row
Round 15, same yarn, hdc in each stitch
Round 16, white (slightly brighter than Rnd 1's white), sc in each stitch, occasional small spike into triple crochets of Rnd 13
Round 17, 18 and 19, Swiss blue, sc (I think). I thought I was finishing off the hat. Then I tried it on... which brings me to...
Round 20, heather gray wool yarn, row of sc
Round 21, same yarn, hdc, but I put the hat on and marked with a piece of yarn where my ears were and put a single shell at each point in the round
Round 22, black wool, more hdc, then where the shells of Rnd 21 were I skipped the four or five stitches before and after the shell top and did 10 triple crochets into that one stitch. I think I was losing my mind by this point and just wanted to be DONE (I'd been working on it all afternoon).
Round 23, rust-colored, sc with ridiculously giant spike stitches into Rnd 19. That's four sc, then a spike stitch, four sc, spike stitch, etc.
THEN I was done. I hope this helps!
And here's looking down into the wrong side of the hat- you can see where I roughly tied off the yarn as I switched colors. You can't tell from the outside:
Thank you for your wonderful comments!!
p.s. to bluedisaster- Your dad sounds like a wise man.
and to Teeta- I actually did laugh out loud reading your post!