Ed, here goes your answer according to wikipedia:

“Chowder is any of a variety of soups, enriched with salt pork fatback and thickened with flour, or more traditionally with crushed ship biscuit or saltine crackers, and milk. To some Americans, it means clam chowder, made with cream or milk in most places, or with tomato as "Manhattan clam chowder." Corn chowder is a thick soup filled with whole corn (maize) kernels. Chowder is often commonly associated with New England cuisine.”

“Bisque is a highly-seasoned thick, creamy soup of puréed shellfish, of French origin. It can be made from lobster, crab, shrimp or crayfish. It is thought the name is derived from Biscay, as in Bay of Biscay, but the crustaceans are certainly bis cuites "cooked twice", for they are first sautéed lightly in their shells, then simmered in wine and aromatic ingredients, before being puréed. Bisque is a method of extracting every bit of flavor from imperfect crustaceans not good enough to send to market; if the shells are not ground to a fine paste and added to thicken the soup, it is not really a bisque.”