CLASS I 



PELECYPODA 



493 



Recent ; represented by about 200 fossil and as many recent species. Very numerous 

 sub-divisions have been proposed ; Venus s.s. is typified by V. mercenaria Lam. 



FiQ. SOS. 

 Venus eincta Eichw. Miocene ; Gainfahrn, near Vienna. 



Fia. 809. 



Meretrix semisulcaia Lam. 

 Eocene ; Grignon, near Paris. 



Meretrix Lam. (Gytherea auct.) (Figs. 809, 810). Hinge witli lateral teetli. 

 Macrocallista Meek ; Callocardia Adams ; Saxidomus Conrad. Tertiary and Recent. 



Fig. 810. 

 Meretrix incrassata Sow. Oligocene ; Weinheim, near Alzey. 



Pig. 811. 



C i r c e e x i ?« i a 

 Hoernes. Miocene ; 

 Enzesfeld, near 



Vienna. 



Tivela Link. Hinge witli supplementary cardinals. Miocene to Recent. 

 b. Girce Scliiim. (Fig. 811). Gafrarium Bolten. Umbones compressed, sculj^ture 



often divaricate, ligament immersed. Tertiary and Recent. 



Subgenus Gouldia Adams. 

 Eocene to Recent. 



raphia 

 Sarniatian 

 Vienna. 



Fig. srJ 



gregar ' 

 Stage ; 



ia Partsch. 

 Wiesen, near 



Small, concentrically striated. 



Ptychoniya Agassiz. 

 Cretaceous, 



c. Paphia Bolten 

 Pul- 

 se- 

 less 

 with 



813. 



Paphia (Baroda) fmgilis (d'Orb.). 

 Upper Cretaceous ; Gosau, Austria. 



(Tapes Megerle ; 

 lastra Sow.) (Figs. 

 814). More or 

 elongate, oval, 



hinge - plate, 

 and often 

 bifid cardinals, no la- 

 terals, and deep pallial 

 sinus. Cretaceous to 

 Recent; about 150 

 living species. 



narrow 

 divergent 



