The Collaborative International Dictionary
                    Ephippium
                    
                        
                
                                                                    Ephippium \E*phip"pi*um\, n. [L., saddle cloth, fr. Gr. ?; 'epi` on + "i`ppos horse.]
- (Anat.) A depression in the sphenoid bone; the pituitary fossa. 
- (Zo["o]l.) A saddle-shaped cavity to contain the winter eggs, situated on the back of Cladocera. 
Wiktionary
                    ephippium
                    
                        
                
                                                                    n. 1 (context anatomy English) A depression in the sphenoid bone; the pituitary fossa. 2 (context zoology English) A saddle-shaped cavity to contain the winter eggs, situated on the back of Cladocera.