CLASS I 



PELECYPODA 



489 



Kelliella Sars ; Lutetia Desli. ; (?) Allopagus Stol. ; Turtonia Alder. Eocene to 

 Eecent. 



C Cyclodonta. 



Teeth arched, springing from below the hinge margin, with the hinge-plate obscure or 

 absent. 



Superfamily 9. CARDIACEA Lamarck, 



Lobes of the mantle free behind the sij)hons, foot elongate, geniculate; sculpture of 

 the shell chiefly radial ; cardinal teeth conical, the lateral laminae short, distant from the 

 cardinals. 



Family 26. Cardiidae Fischer. 



Shell substance cellulo-crystalline, ivith the external layer more or less tubular ; valves 

 equal, free, gaping slightly behind, the beaks prosocoelous, the margins usually serrate or 

 radially striated ; adductor scars sub-equal, the pedal distinct and usually distant ; 

 ligam.ent and resilium parivincular, external, short, set in a groove ; area obscure ; com- 

 plete hinge armature consisting of an anterior and posterior lateral in the left, and tmo 



A ■ B 



Pio. SOI. 

 CarcUum product um Sow. Turonian ; St. Gilgeii, Salzburg, i/i- 



anterior and one posterior lateral in the right valve, any or all of which may be absent ; 

 cardinal formula ^oTyfrnj ^he teeth simple, smooth, never bifid, one cardinal in each valve 

 usually persistent, the others inconstant. Trias to Recent. 



Gardium Linn. (Figs. 801-803). Cordate, inflated, radiately ribljed or striated, 



Fio. SO'2. 



Protoeu rdia hifrons 

 Reuss. Turonian; 

 Strobl- Weissenbach am 

 Wolfgangsee, Austria. 



Fki. 803. 



Cardium {DUcors) diacrepans Bast. Miocene 

 Dax, near BordeaT'x. Vl- 



