Rex Trulove
Button mushrooms, crimini mushrooms, white mushrooms, table mushrooms, portabello mushrooms, Italian mushrooms, Swiss mushrooms, chestnut mushrooms, and common mushrooms are all names that refer to exactly the same kind of mushroom; Agaricus bisporus. These are the most commercially grown and sold mushrooms in the world. They also grow wild in Europe and North America, where they are often known as field mushrooms.
Learned another fact Rex.
Some stores try to charge more by using different names, too.