Description: Cross section of the omasum, which is also called the manyplies, psalterium or third stomach of ruminants. This small, oval organ connects the reticulo-rumen to the abomasum in true ruminants. It is absent in the Camelids (Tylopods). Leaves of tissue hang down from the distal wall of the organ to the omasal canal like the leaves of a book. This slows rate of passage of digesta from the reticulo-rumen and forces particles to be reduced to a minimum size capable of passage. Some absorbtion of water, volatile fatty acids, ammonia and electrolytes (Na, K) also occurs. In a mature bovine this oval organ can measure 8-10 inches across by 10-12 inches long.