HALIOTIS SEA-EAR. 117 



When a new hole is opened, one toward the 

 spire is closed, and there are seldom more than 

 seven or eight unstopped at the same time. 

 When the Haliotides traverse the rocks, their 

 shell is like a reversed basin, and the circum- 

 ference is bordered by the foot of the animal, 

 which is very large ; the spire is at the posterior 

 part as it advances. In their repose they adhere 

 to the rocks with such tenacity that it requires 

 the utmost force to disengage them, though they 

 can with the greatest facility remove themselves. 

 They are always found near the surface of the 

 water, and in serene summer nights they feed on 

 the vegetation which springs up on the shore. 

 All the shells of this genus are marine, as the 

 name implies, being derived from fas (hals) sea, 

 and wra (bta) ears. Most of the species inhabit 

 the seas of warm climates. They have no oper- 

 culum. 



HALIOTIS Tuberculata* 



COMMON SEA-EAR. 



Specific character. Shell strong, thick, sub- 

 ovate, transversely wrinkled, striated longitudi 

 nally, and tuberculated ; near the inner margin 

 is a ridge extending the length of the shell, and 

 terminating in one spiral turn at the end, a little 

 produced; this ridge is beset with tubercles 

 which increase in size as they recede from the 



* Plate IV. figure 2. 



