Morphology Crotche: the Dorsal (thoracic) shows. 1 - system of dental cavities and tooth articulation of pan to each other. 2 - an elasticity of ligaments that cause shellfish to be open. If the Anterior Crotche Bashdbh Prosogyrate say it. If the Posterior Crotche is it called Opisthogyrate. If Crotche is direct and not inclined to any side, Orthogyrate name is called. Appendage beside Beak, mumps (Auricle) say. In the two samples are unequal mumps part of the bigger shows for Anterior .