Correct:
SNAIL SHELL:
Rnd 10: 9 ch, [4 dc, 2 dc in next st] 4 times, 9 dc.
42 sts
HEAD AND BODY
Rnd 21: [1 dc, 2 dc in next st] 2 times,
56 dc, [1 dc, 2 dc in next st] 2 times.
68 sts.
Rnd 22: [2 dc, 2 dc in next st] 2 times,
56 dc, [2 dc, 2 dc in next st] 2 times.
72 sts.