PANOPiEA. 173 



doubtless furnished the disturbing medium. These dan- 

 gerous and disastrous consequences of too great an imbi- 

 bition of the " pure element" present a timely warning to 

 the votaries of teetotalism. 



PANOP^A, Menard de la Groye. 



Shell transversely oblong, rather compressed, equivalve, 

 more or less inequilateral, gaping at both extremities ; sur- 

 face of the valves nearly smooth or transversely furrowed, 

 never longitudinally ribbed ; pallial impression in each 

 valve very strongly marked, with a deep triangular sinus 

 posteriorly ; muscular impressions strong and oblong ; 

 hinge formed of a conic cardinal tooth in each valve lodged 

 in a cavity in the valve opposite ; ligament external, short, 

 prominent, attached to strong nymphal callosities. 



Animal oblong, and furnished with a very long and ex- 

 tensible siphonal tube; body and tube invested with a 

 wrinkled brown leathery epidermis, continuous with the 

 shell ; mantle closed throughout its length, except a small 

 opening with thickened lips in front anteally for the pas- 

 sage of a short stout muscular foot ; adductor muscles very 

 strong; mouth surrounded by thickened lips bearing four 

 labial pali3i ; siphonal tubes united to their extremities ; 

 orifices inconspicuously fimbriated. 



This genus was founded by Menard de la Groye in the 

 ninth volume of the "Annales du Museum"" (1807), for the 

 reception of an Italian tertiary fossil, closely related to the 

 " Chama glycimeris''' of Aldrovandus, a shell which had 

 latterly been known as Mya glycimeris. The founder of 

 the genus recognised their affinity, and also their relation- 

 ship to Mya and neighbouring genera. The PanopcctE in- 

 deed closely resemble Myce^ both in the general aspect of 



