PANOPEA. 75 



But neitlier of these zoologists appears to have seen it 

 alive. A great many species are known, both recent 

 and fossil, some of' the latter being Oolitic, and others 

 (according to D^Orbigny) Permian. 



The name of this genus has been spelt in various ways. 

 Besides the original and correct one which I have given, 

 Goldfuss and others called it Panopcea, Swainson Pano- 

 pia, and Nyst Panopcea. P. glycymeris is the type of 

 Klein^s genus Glicimeris, which name has precedence 

 of Panopea by more than half a century ; but Glycimeris 

 is now used for another well known genus. 



Panopea plica'ta*, Montagu. 



MytUus'pUcafus, Mont. Test. Brit. Suppl, p. 70. Saxicava rugosa. young?, 

 F. & H. i. p. 149, pi. vi. f. 1-3, and app. iv. p. 248. 



Shell rhomboidal, considerably dilated towards the posterior 

 end (where the gape is very long, although not much wider 

 than that of the anterior side), compressed, especially in front, 

 thin, of a nacreous texture, semitransparent, and somewhat 

 glossy : sculphire, numerous fine but irregular concentric striae 

 or plaits, and the surface in perfect specimens is minutely and 

 partially granulated : colour milk-white : epidermis extremely 

 thin, pale yellowish-white : margins rounded on the anterior 

 side, nearly straight in front, expanding and arched (although 

 obliquely truncated) on the posterior side, and forming a high 

 shoulder at the back, with a distinct but blunt keel or ridge 

 from the beak to the lower angle ; anterior dorsal margin very 

 short : leaks small, shghtly inflected and calyciform as in 

 Mya Bingliami : ligament yellowish -brown : Jmige-liyie nearly 

 straight : hinge-plate rather narrow but reflected, and forming 

 in the left valve a slight groove on the outside ; it is furnished 

 with a triangular process for the ligament, which slants a little 

 inwards obliquely, like the tooth or cartilage-pit in Mya ; this 

 process varies in position, as well as in shape and size : tooth 

 very minute, and not always present : inside porcellanous, and 

 somewhat iridescent : pallial scar very distinct, with a shallow 

 sinus : ^nuscidar scars irregularly triangular. L. 0-25. B. 0-4. 



Habitat : Skye (Laskey) ; among trawl refuse from 



* Plaited. 



e2 



