The Common Dogfish can hardly be distinguished from the ' Sweet William' previously mentioned, except by his defensive and offensive spines. He has several local names, such as bone-dog, sea-dog, and hoe in Orkney, and skittle-dog in Cornwall, but most common are spur-dog and spiked or picked-dog, these three names evidently having reference to the spines. These spines inflict really dangerous wounds, so that the very best thing to be done with one of these fish is, to lift it in by line, landing net, or gaff, and drop it on the floor of the boat. Then place a foot on it to keep it still, chop off its head, and, taking the carcase gingerly by the tail, cast it overboard as ground-bait. In many placesóWest-country, Ireland, and the Hebridesóthese fish are eaten either fresh, salted, or merely dried. Oil is extracted from their livers, and their garbage is good manure. They are simply ubiquitous, but are most plentiful in those waters most frequented by pilchards and herrings. Some thirty-seven years ago an enormous shoal of sea-dogs reached from Uig to Aberdeen.