422 MOLLUSCA SUB-KINGDOM VI 
amphidetic ; the chondrophore is received into a socket of the opposite valve, not merged 
with the valve margin ; hinge with one or two sub-umbonal projecting teeth, and rarely 
obscure traces of laterals; the 
posterior gape tnconspicuous ; 
siphons short, united, naked, 
wholly retractile. Trias to 
Recent. 
Corbula, Lam. (Figs. 779, 
780). Small, ovate, rostrate, 


Fic. 780. 
WG. 778 . ve inequivalve, the 
= Fic. 779. A, Corbula carinata, Duj. Ty ee! ? th : ight 
Corbula (Bicorbula) gallica, Lam. Miocene; Potzleinsdorf, near valve convex, larger, with a 
Caleaire Grossier; Damery, near Vienna. B, C. angustata, Sow. ,.,, oon. - _ 
Epernay, France. Hinge, 1/}. Upper Cretaceous ; Gosan. prominent tooth es front of 
the pit for the resilium, left 
valve with a flattened chondrophore, and usually a posterior tooth. Trias to 
Recent. 
Sub-genera: Hrodona, Daudin (Azara, d’Orb. ; Potamomya, Sow.) Pallial sinus obsolete, 
fluviatile. Pleistocene and Recent. Bothrocorbula, Gabb. With a lunule deeply indented 
into the cavity of the valves. Tertiary and Recent. Corbulamella, Meek. With an anterior 
myophore. Cretaceous. Anisothyris, Conr. (Pachydon, Gabb). Pliocene. Paramya, Conr. ; 
Corbulomya, Nyst. Tertiary and Recent. 
Family 43. Saxicavidae. Gray. 
Shell substance as in Mya ; epidermis conspicuous ; valves equal, free, rude, and often 
irregular, more or less elongated and gaping, not fully covering the animal; adductor 
scars often irregular, the pallial 
line discontinuous or irregular, 
the sinus distinct ; shell margins 
smooth ; «area obsolete; liga- 
ment and resilium external, 
parivincular, seated on strony 
nymphs, sometimes widely ex- 
tended : hinge without laterals, 
with few feeble or obsolete swb- 
umbonal cardinals, Cretaceous 
to Recent. 
Savicava, Fleuriau (Gly- 
cimeris, Schum.; Hiatella, 
Daudin ; Byssomya, Cuvier ; 
Agina, Turton). Hinge eden- 
tulous in the adult, with one 
or two cardinals in the young, 
boring in the softer rocks. 
Tertiary and Recent. Sub- 
genus Panomya, Gray (Chaen- 
opea, Mayer). 
Panopea, Menard (Glyeci- ry Ga 
meris, Lam. 1799, non Da saeisirge 

=e s Panopea Menardi, Desh. Miocene; Vienna Basin. A, Dorsal 
Costa), (Fig. 781). Large, view of valves. 3, Internal cast. C, Hinge plate seen from above, 1/y. 
gaping widely behind and 
slightly in front; surface concentrically, or feebly sculptured ; an obscure tooth in 
each valve. Cretaceous to Recent. 
Cyrtodaria, Daudin (Glycimeris, Lam. 1801). Solenoid with strong epidermis. 
Pliocene and Recent. 
