22 PANDORIDvE. 



esteemed as S. siliqua. The flavour is said to be pecu- 

 liar. Poli mentions its being so acrid, that none but 

 the poorest would use this kind for food. The shell 

 differs from that of the last-named species in being more 

 regularly cylindrical, deeper in proportion to its breadth, 

 and of an orange-grey instead of a purplish-green colour ; 

 the diagonal compartment is less marked ; the sides are 

 more truncated ; the anterior end is constricted ; and it 

 has fewer teeth. 



Linne's description of S. vagina in the ' Mus. Lud. 

 Ulr. Reg/ is peculiarly appropriate to this species, 

 although in the 12th edition of the c Syst. Nat.' he 

 appears to have united with it an Indian species which 

 has been named S. truncata by W. Wood. Our species 

 (as a mollusk) is the Hypogaa tentaculata of Poli, and 

 (as a shell) the S. marginatus of Pulteney and Donovan. 

 The last-mentioned author said it was not the S. vagina 

 of Linne, but he gave no reason for saying so. 



Family XVII. PANDO'KID^, Gray. 



BODY oval or oblong : mantle having a slit on the anterior 

 side for the passage of a foot, and forming on the other side a 

 tubular sheath : tubes short, united nearly to their openings, 

 which are fringed : gills two on either side, each pair being 

 more or less united, long, narrow, and slightly curved : palps 

 corresponding in number with the gills, and triangular : foot 

 tongue-shaped. 



SHEI^L oval or oblong, inequivalve, pearly, gaping at the 

 posterior side, which is flexuous and elongated, and projects 

 upwards : beaks very small : cartilage at the posterior side, 

 wholly internal, long and oblique : hinge strong : teeth, either 

 a single cardinal in each valve, or an oblong plate, which is 

 attached only to the cartilage and partly covers the hinge: 

 pallial scar slight, and narrowly sinuated: muscular scars 

 small. 



