Z5S, 



PANOP^A. 



TESTA ovalis, aequivalvis, inaequilateralis, utrin- 

 quehians, praecipufe ad extremitatem posticam ; 

 dente oardmali in utraque valva unico, aciito ; 

 impressionibus muscular thus duabus, distantibus; 

 impressione rnusculari pallii sinu maximo ; 

 ligamento magno, externo, fulcro maximo. 



This Genus, which belongs to the family of Solenaceae, 

 is remarkable for the acute-pointed tooth in the hinge of 

 each valve, and for the very large fulcrum to which the 

 ligament is fixed. Its species, as far as are already known, 

 are very few, not more than four or five, of which two 

 or three are recent and one or two fossil. The principal 

 and well known recent species is found in the Mediter- 

 ranean ; a second has existed in our own collection for 

 many years, it was sent to the late G. Humphrey from 

 New South Wales ; and we have been informed that another 

 has been dredged at Scarborough. The fossil species 

 belong to the tertiary beds. Though not at all agreeing 

 with the characters of that Genus, the only species known 

 to Linnaeus was placed whh Mi/a; probably on account of its 

 external resemblance ; it will however easily be perceived 

 that the two Genera are very distinct, the Panopaea 

 having a sharp-pointed tooth in each valve, and an external 

 ligament attached to a large fulcrum externally, while the 

 Mya has a large, broad and blunt tooth in only one valve, 

 and an internal ligament attached to that tooth. 



Shell oval, equivalve, inequilateral, gaping at both 

 ends, but principally at the posterior; with a single acute, 

 cardinal tooth in each valve; muscular impressions two, 

 distant ; muscular impression of the mantle with a large 

 sinus; ligament large, external, affixed to a very large 

 and prominent fulcrum. 



