Page:Natural History, Mollusca.djvu/160

148 is so open as to display the whole interior even to the summit.

The Gaping Bulla is common on our coasts, especially in the south, inhabiting muddy and sandy ground at a few fathoms' depth. I have dredged it abundantly in Weymouth Bay, a mile or two from shore. In captivity it is sluggish, remaining inert at the bottom of the vessel in which it is kept, so as to be an uninteresting subject of observation; added to this it continually secretes and discharges a viscid slime, which stretches through the water in long tenacious strings, and envelopes and distresses any other marine animals which may be its fellow-captives. Some of the Nudibranchs discharge mucus in the same manner; but I know of none that possesses the disagreeable quality to the same extent as this Bulla.