Row 1: Sc in 2nd ch from hook and each ch across – 37 sts.
Row 2: Ch 1, turn. Sc in each st across.
Rep Row 2 until piece measures about 10 in. (25.5 cm) from beg.
Next Row: Ch 3 (counts as 1st dc), sk next sc, work 1 dc in next sc, * skip 4 sc, (dc, ch 1, dc, ch 1, dc, ch 1, dc) in next st – Shell made; rep from * across, end last rep skip 4 sc, 2 dc in last sc.
Next Row: Ch 3, turn. Skip next dc, dc in next dc, *work Shell in center ch-1 space of Shell; rep from * across, end 2 dc in last dc.
Rep last row until piece measures about 13 in. (33 cm) from beg.
Fold lower edge of bag up about 5 in. (12.5 cm), and seam sides. Sew on button. Weave in ends.