Ideal%20introduction%20to%20the%20most%20familiar%20and%20unique%20types%20of%20seashells%20found%20in%20the%20marine%20eco-regions%20of%20North%20America.%20This%20beautifully%20illustrated%20guide%20highlights%20over%2085%20species%20and%20includes%20a%20marine%20ecoregion%20map.%20On%20waterproof%20paper%20for%20durability%2C%20this%20pocket%20guide%20is%20ideal%20for%20field%20use.