modified single crochet

I would love to make this wrap as a gift for a friend but I can't get past the foundation row!! It is a pattern from made from spa yarn and it is called oasis wrap. I do not understand the instructions for "mod-sc".Pattern begins with "ch2 ,sc in top loops of second ch from hook(counts as mod-ch),*ch1, mod-sc in previous sc;repeat from * until 195 mod-sc have made, ch1-195 mod-sc".Then onto round two.I am stumped by the mod-sc in previous sc. Where is that previous sc?????????????? P.S. the pattern is free online at if anyone would be willing to take a look and help me understand this technique. A picture of the stitch would really help if anyone knows where to find one!