BRACHIOPODA. 



329 



Family 1.— TEREBRA TULIDJE. 



The description of this family is clearly given in that 

 of the order. 



These singular Molluscs inhabit great depths. Pro- 

 fessor Owen observes that " both the respiration and 

 nutrition of animals which exist beneath the pressure of 

 from sixty to ninety fathoms of sea water, are subjects 

 suggestive of interesting reflections, and lead us to con- 

 template with less surprise the great strength and com- 

 plexity of some of the minutest parts of the frame of these 

 diminutive creatures." 



They fix themselves to other objects, and also to each 

 other, by a tendinous cord, which proceeds from the hole 

 in the boss. They have a curious kind of internal skele- 

 ton, as it may be termed, consisting of a slender, flattened, 

 calcareous hoop, with other pieces diverging from it ; this 

 apparatus is for the attachment of the arms of the animal. 

 The shells have no brilliancy of colour, but are generally 

 of a dull brown. Some of them are striated or grooved 

 outside, and toothed at the edge, locking firmly into cor- 

 responding teeth in the other valve. They are found in 

 the European seas, those of New Zealand, and the Southern 

 Ocean. The fossil species are very numerous ; they have 

 been termed the " fossil aristocracy," from the incalcul- 

 able antiquity of their lineage. They are admirably illus- 

 trated in Sowerby's ee Mineral Conchology." 



Terebratella. Z>' Orb. — Shell of a punctured tex- 

 ture, generally broader than long, inequivalve ; the upper 

 valve has a straight obliquely truncated boss, from which 

 springs a distinct area ; the under valve is generally flatter 

 than the upper, and has the hinge line nearly straight; 



