I'm pretty sure Chaudin is pork stomach, and Ponce is just another word for it. Chaudin, though really refers to the final stuffed and cooked dish and ponce, the stomach itself. Calf stomach may have been used at one time, but not much now.
An Acadian Lexicon
Andouille (ohn-DOOEY): Sausage of lean, smoked pork, spicier than French andouille.
Boucherie (boo-shuh-REE): A festive hog slaughter, with several families helping prepare the sausages, cracklings, head cheese, chops, and roasts.
Boudin (boo-DANH): A peppery, pale brown, boiled link of meat, onions, and other seasonings, bound with rice. Boudin blanc has lean meat and fat; boudin rouge (similar to boudin noir in France) is made with pig's blood.
Boulettes (boo-LETS): Ground crawfish, shrimp, or crab formed into balls with seasoned bread crumbs and deep-fried.
Chaudin (sho-DANH): Baked or boiled calf's stomach, usually stuffed with seasoned ground pork or veal and sliced for serving.
Chaurice (sho-REESS): Like Mexico's chorizo, pork or beef sausages flavored with cayenne, which gives them a deep red tint.
Couche-couche (koosh-koosh): A breakfast cereal of cornmeal, panfried or steamed and eaten with milk. From the North African word "couscous."
Courtbouillon (KOOR-boo-yanh): In Acadiana, a stew of fish and shellfish in a dark, rich, much-reduced broth. In Creole New Orleans, fish (especially redfish) cooked with tomatoes, bell peppers, and onions.
Étouffée (ay-too-FAY): Literally, "smothered." The classic is crawfish étouffée, with the tails smothered in a heavy, lidded pot in crawfish fat, with onions, bell peppers, scallions, and parsley.
Filé (fee-LAY): Thickener made from powdered sassafras leaves, a contribution of the local Native Americans.
Gâteau au sirop (gah-TOE oh see-ROE): A dark, moist dessert cake, sweetened with sugarcane syrup.
Gratons (grah-TAWHNS): Pork skins fried in lard.
Gumbo: From the African Congo word for okra, "quingombo." Acadian gumbo—thinner (but no less rich) than the Creole version—is made with various combinations of duck, guinea hen, chicken, sausage, and shellfish, and is thickened with okra or filé.
Jambalaya (jum-buh-LIE-uh): Akin to paella; a dish of rice with shellfish, especially oysters, plus chicken giblets, sausage, and tasso.
Maque-choux (mock-SHOO): Corn (introduced to the Acadians by Native Americans), cooked with tomatoes, onions, and bell peppers.
Ponce (pawhnss): Baked or boiled pig's stomach, stuffed, like chaudin, with seasoned ground pork (and sometimes yams), and sliced for serving.
Roux (roo): Flour browned in lard or oil to form a thickener for stews, gravies, and gumbos; color ranges from "blond" to "dark."
Sauce piquante (sohss pee-KAWNT): Not a sauce but a cayenne-dosed stew of chicken, turtle, rabbit, or fish—and sometimes even alligator.
Tasso (tas-O): Spicy, dry-cured pork or beef jerky.
