UNIVALVES — HALIOTIS. 179 



HALIOTIS Sea-ear or Ear-Shell. 



DESCRIPTION OF PLATE XXXI. 



DiT. I.-—Fam. I. Fig. 2. H. chracherodii. Fam. I. Fig. 4. H. iris. 



Fam. 1. Fig. 5. H. pulcherrima. Fam. 2. Fig. 3. H. asinina. 



Dnr. II.— Fig. 1. H. imperforata. 



Shell univalve, dilated, ear-shaped, generally with a longitudinal 

 row of orifices along the surface ; spire lateral, and nearly concealed. 



THE general form and appearance of the shells of this 

 beautiful genus are so similar, that it is often difficult 

 to distinguish and anange the species. In shape they 

 greatly resemble the human ear; the only excep- 

 tion is the H. asinina, which has received its name 

 from being more elongated than any of the other 

 species. 



The exterior is generally composed of rugee or tu- 

 berculations, over which pass approximate, elevated 

 striae : but as it is usually loaded with marine substan- 

 ces, or much decayed and worn, this character is seldom 

 observable. The interior of the Haliotis is remarkable 

 for its natural and splendid iridescence, which fonns a 

 striking contrast with the sombre appearance of its ex- 

 terior. The iridescent colors are exhibited in the 

 highest splendor, in the H. iris, H. rufescens, and H. 

 splendens. 



The back of the Haliotides of the first division is 

 furnished with a row of orifices near the margin, vary- 

 ing- in number from eight to thirty-eight ; of these from 

 N2 



