358 veneridjE. 



ers M or u pullets " in some parts of Devonshire. De 

 Gerville says that the people of La Manche sell this 

 kind for eating, under the name of " Coque." Its vulgar 

 appellation in Shetland is " Kullyak," being probably 

 derived from the Norse word " kulle," a haddock, this 

 mollusk being a favourite bait for fish. It is also not 

 an unpalatable article of human food. I tasted one 

 raw at the recommendation of Dr. Edmondston, and 

 fancied that its flavour was not inferior to that of an 

 oyster. He indeed gave this the preference. The gills 

 appear to be aerated by means of the mantle-edges, 

 which are always swaying about with a wave-like motion. 

 The fry are shaped like the adult, but are quite smooth 

 and glossy. My largest specimen was found by Edward 

 Forbes in Skye, and is 2 inches long by 2 J inches broad. 

 Monsters of another kind occasionally make their ap- 

 pearance, being distorted in one way or another, chiefly 

 in being twisted or inequivalve. 



This shell differs from T. virgineus in being oval in- 

 stead of oblong, less glossy and never polished, and in 

 the ribs being much finer, more numerous, and de- 

 cussated by longitudinal striae. Forbes was the first 

 who publicly repudiated (in his c Malacologia Monensis') 

 the claims of Venus perforans to specific distinction, 

 justly considering it to be only a variety of T. pullastra. 

 Nine years previously, when I was also a juvenile con- 

 chologist, I formed a similar opinion ; and in the mean 

 time Clark made the excellent observations, which were 

 transferred from his note-book to the pages of the l Bri- 

 tish Mollusca,' embodying the views of the consenta- 

 neous triumvirate. The normal coloured markings are 

 present in some specimens of this form which had been 

 immured all their lives in rocks and secluded from the 

 garish light of day. One living example, which occu- 



