456 



MOLLUSCA 



PHYLUM vr 



Family 32. Trigoniidae Lamarck. 



Shell with few hinge teeth (5), the mantle lubes wholly free, but so applied to each 

 other in life as to form functional siphons ; pallial line simple. Devonian to Eecent. 



Schizodus King (Fig. 700). Ovate or quadrate, sniootli ; lateral teetli not fluted ; 

 anterior adductor scar witli a small radial buttress. Abundant m the Permian. 



Myojjhoria Bvonn {Neoschizodus . Gieb.) (Figs. 701, 702), 



Smootb or radially sculptured, ^^^J^ ^J usually witli a strong 



radial ridge extending from the 

 downward to the basal margin ; 



uml)ones backward and 

 the sculpture on the areas 



Schizodus ohscuriis Sow. Zechstein; Nieder- 

 rodeDbach, near Hanau. .4. Internal mould, 

 i/i- TJ, Hinge, Vl (=ifter King). 



Fig. 701. 



Myophirria laevigata 

 (All)erti). Schaumkalk ; 

 Riidersdorf, near Ber- 

 lin. ■ i/i. 



Ftci. 702. 



Myoplioria dccussnta Miin.st. 

 Upper Trias ; St. Ca.ssian, Tyrol. 

 A, Exterior of right valve, Vi- 

 li, Enlarged view of liinge. 



Fig. 703. 



Trigonia navis Lam. Lower Brown Jura ;' 

 Gunder.sliofen, Alsace. i/i.| 



Fig. 704. 



Trigonia daudala Park. Middle Cretaceous 

 (Hervien); Meule de Bracquegnies, Belgium. Vi- 



Fig. 705. . 



Trigonia costata Sow. 

 Middle Jura ; Wiirtembeig. 



Fig. 706. 



.Trigonia cf. aliformis Park. Senoiiian ; 

 Vaels, near Aix-Ia-Chapelle. i/i. 



Trigonia jicctinata 

 Lamarck. Becent; Au.s- 

 tralia. Hinge, i/i. 



