Studies on structure and function of digestive system of Cymatium pileare

The digestive system of Cyrnatium pileare consists of buccal cavity,oesophagus,stomach,intestine,anus,salivary glands and liver.There is a contractible "Argobuccinum" form proboscis in the anterior extremity of its body,and the buccal cavity lies in the anterior part of the proboscis,with a pair of jaws and a piece of radular ribbon.The jaws have many neatly arranged sickleshaped sharpen denticles.Its dentition formula of radula is 2·(7) 1·(5~6) 1 (5~6)·1 (7)·2.In the middle of oesophagus,there is an expanded crop,which has the function of temporary food storage and preliminarily digesting food.The stomach is U-shaped and there are 2 entrances for liver ducts in its ventral side.The intestine is short and can be divided into 2 parts based on the structure of epithelia of their inner walls.The inner wall of foreintestine is stratified columnar epithelium,but the inner wall of hindintestine is pesudostratified columnar epithelium.The salivary gland of C.pileare is toxic gland and the toxin extracted from it plays a great role on its predation.The liver of C.pileare is compound tubuloacinar gland with mitochondrion,rough endoplasmic reticulum,Golgi complex and lysosome in its glandular cells.