UNIVALVES—HALIOTIS. 179 
HALIOTIS._Sera-car or Ear-SHELL. 
DESCRIPTION OF PLATE XXXI. 
Drv. L.Fam.1. Fig. 2. H. chracherodii. Fam. 1. Pig. 4 H. iris. 
Fam.1. Fig. 5. H. pulcherrima. fam. 2. Fig. 3. H. asinina. 
Drv. I].—-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 arrange the species. In shape they 
greatly resemble the human ear; the only excep- 
tion is the H. asinma, which has received its name 
from being more elongated than any of the other 
species. 
The exterior is generally composed of rugze or tu- 
berculations, over which pass approximate, elevated 
strie; butas it is usually loaded with marine substan- 
ces, or much decayed and worn, this character is seldom 
observable. The interior of the Halictis is remarkable 
for its natural and splendid iridescence, which forms 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 
