HALIOTIS. 



TESTA aiiriformis, lata, ssepius planiusciila, 

 spird brevissima, depressa sublaterali. Aper^ 

 tura amplissima, ovata. Discus serie forami* 

 num, labio columellari parallelo, pertiisus. 

 Columella pleFiimcjiie planiilata. Testa intus 

 margaritacea. 



With the exception of a few that are commonly knowji 

 by Collectors and Linneans as Imperforate Ear-shells, the 

 Genus Haliotis has not suffered any dismemberments. An 

 attempt has indeed been made by Montfort to separate 

 from the genuine Haliotkles two or three species under the 

 name of PadoUus, in which he has heen followed by Leach, 

 but as far as respects general adoption this attempt ap- 

 pears to have been as unsuccessful as it was unnecessary. 

 Not so the separation of the imperforate Haliotides, which 

 are easily distinguished by wanting the row of perfora- 

 tions so very characteristic of the true Haliotis. 



The name of this Genus is taken from its general 

 resemblance in form to an ear; it is commonly ovate, 

 sometimes nearly round and sometimes oblong, generally 

 broad and rather flat, with a very short, for the most 

 part depressed, rather lateral spire : the aperture almost 

 as large as the shell, ovate or oblong, mostly entire, not 

 quite so in those species c'alled Padollus, by Montfort, on 

 account of the longitudinal _ grooves in their disks. A 

 series of perforations parallel to the columellar margin is 

 remarkable in the disk of the shells of this Genus : as the 

 animal increases in size the smaller of these perforations 

 or those nearest the spire become closed, so that there 

 ?^re seldom more than seven or eight open at one time; 



