In large bowl, stir together Muenster cheese, shrimp, onion, salt, pepper and eggs; set aside. Unroll crescent roll dough onto lightly floured surface. Pinch together perforations on both sides of dough. Fold in half crosswise and with a lightly floured rolling pin, roll out to 14x9 inch rectangle. Brush with butter. Spread cheese-shrimp mixture in a 2 inch strip along 1 long edge of dough; roll up as a jelly roll. Firmly pinch seam and ends together, then moisten slightly with water and smooth lightly with dull edge of knife to seal dough well. Lift roll onto ungreased cookie sheet. Brush with egg-yolk mixture. Bake in preheated oven 400F for 25 minutes or until golden brown. Cool on rack 20 minutes. With sharp knife, cut in 1/2 inch slices. Makes 28.