CONCHIFEEA. 



285 



The only recent species, T. pectenata, which is found 

 in the deep seas of New Holland and New Zealand, was 

 formerly so rare that even an odd valve has been sold at a 

 high price. The interior is lined with highly iridescent 

 mother of pearl, tinged with purple and gold colour. The 

 animal has a strong muscular foot, for when Mr. S. Stutch- 

 bury was procuring some specimens in their native seas, 

 he laid them in the boat, when they leaped over the side, 

 and regained their freedom ; a few minutes more and these 

 lively animals would have been placed in spirits to pre- 

 serve them as specimens. 



Fossil remains of this genus are very numerous. Dr. 

 Mantell says the shores near Boulogne harbour are strewn 

 with them.* 



Schizodus. King. — Shell equivalve, inequilateral ; 

 each valve with two small teeth close to the boss, those 

 of the left placed before those of the right, the hinder 

 tooth of the left valve is on its free side more or less 

 cloven, and locks in with the two teeth of the right valve. 

 — Fossil. 



The type is Axinus obscurus of Sowerby. 



Family 19. — UNION A CEA. 



The animal has the mantle entirely cloven, sometimes, 

 however, prolonged into two short siphons; the foot is 

 generally compressed, and tongue-shaped. The shell is 

 always regular, equivalve, iridescent, covered with a 

 strong, smooth, firm, adhering epidermis; the hinge is 

 variously formed, the ligament is always external ; the 

 muscular impressions are two, the anterior of which is 



* Medals of Creation. 



