42 POPULAR BRITISH CONCHOLOGY. 



Professor Torbes and Mr. M^Andrew in forty fathoms 



water, at Loch Fyne. 

 lY. PoROMYA. — The shell is equivalvCj nearly colourless, 



roundish, with an external ligament, and a kind of 



tooth or excrescence in the hinge of one valve, entering 



a pit in the other. 

 Mr. Jeffreys dredged a specimen of the only species, P. 

 granulata, in fifty fathoms^ depth of water, off the island of 

 Skye. 



PANDORID^. 



As the genera Pandora and Lyonsia contain the only 



British representatives of this family, and as I do not think 



these genera very well united, it will be better to say the 



little that is to be said on them under their respective names. 



I. Pandora. — In this mollusc, besides the narrow space 



in which it is confined, we find no great departure 



from the preceding families. The siphons are rather 



short, divided, with the openings fringed and tinted 



with pink and yellow ; the foot, which is rather large, 



three-cornered, and pointed, protrudes through the 



usual opening in the mantle. The shell is thin, very 



flat, and exquisitely pearly ; one valve is rather deeper 



