194 



A very handsome fossil shell, apparently of this genus, is found in the 

 cliffs at Bognor ; hut as I have never been able to view the interior part, 

 although I have destroyed several specimens for the purpose, I am una- 

 ble to speak decidedly with respect to it. Fragments of the hinge part 

 of a shell of this genus are sometimes found in the neighbourhood of 

 Norwich. 



CXXVI. Panopaa. A transverse inequilateral bivalve, gaping une- 

 qually at the ends. The hinge similar in both valves, having a large 

 elongated tooth placed under the cartilaginal depression, running along the 

 interior edge in a raised blunt margin, and projecting posteriorly ; a coni- 

 cal hinge-tooth, rather flat and bent; and on the right valve, a little 

 pit, which receives the tooth of the opposite valve. The ligament exte- 

 rior ; the beaks but little projecting ; the depression large. Two mus- 

 cular impressions in each valve, towards the extremities. 



This genus was formed by M. Menard de la Groye, on a shell found 

 in Mount Pulgnasco, in the commune of Diolo, in Parma, in a fine- 

 grained quartzose sand, mixed with a greyish clay. Of this shell, some 

 beautiful specimens have been collected by M. Cortezi, of Parma. On 

 clearing the hinge from one of these, which had been presented to 

 M. Faujas, M. Menard was very much surprised to find that it was a 

 shell of a mixed genus, resembling both Mya and Solcn. This shell is 

 about three inches and eight lines in length, and six inches and three 

 lines in width. The outside is smooth, being only transversely grooved by 

 the successive additions of new shell. On the inside, along the edge, and 

 particularly the upper edge, is a callous smooth kind of border ; and, 

 further into the cavity of the shell, is another surface, more or less ru- 

 gose, which marks the parts where the animal was attached. Annales 

 du Mm. Tome ix. p. 131. 



A recent shell of this genus, but. undoubtedly of a different species 

 from the fossil shell described by M. Menard, has long been known to 

 the conchologists. It was first figured by the indefatigable Aldrovandus, 

 who gave to it the name ofChama glycemeris, Testae, lib. in. p. 472. The 



