HALIOTIS Californiensis, 

 Small-holed Californian Ear-shell. 



Gekeric Character. 



Testa unkahis, depressissima, lata, auriformis. Discus admodum perfo- 

 ratus. Spira minvta, depressa, Apertura testam magnitudine peii^ 

 cequans, iiitus margaritifera. 



Typus Genericus H. Tuberculata Linn. &c. 



Shell univalve, greatly depressed, broad, ear-shaped, the disk with 

 many perforations. Spire minute, depressed. Aperture nearly 

 as large as the shell ; inside pearly. 



Generic Type H. Tuberculata Linn. i&c. 



Specific Character. 



H. Testa ovali, Icevi, obscure thalassind ; labio exteriore supra immar- 

 ginato, interiore lato, complanato, foraminibus numerosis, minutis, 

 orbicularibus, loevibus. 



Shell ovate, smooth, obscure sea green ; outer lip above immarginate ; 

 inner lip broad, flat; perforations numerous, very small, orbi- 

 cular and smooth. 



The Ear-shells are strangely characterized by their pecu- 

 liarity of form, perforated holes, and rich pearly interior. They 

 are found in both temperate and tropical seas ; but the defi- 

 nitions hitherto given by conchologists are so imperfect, that 

 they have left our knowledge of these shells nearly the same 

 now, as in the time of Linnaeus. Seventeen species only are 

 enumerated in Mr. Dillwyn's work ; although thirty-four have 

 fallen within my own observation the last few months. 



The difference between this and the common black Cali- 

 fornian Ear, consists in its being a much deeper and smoother 

 shell, always narrowest at the base, the outer lip not having 

 (as in that) a prominent curve or gibbosity where it joins the 

 spire ; but principally in the perforations, which in this are 

 always half as large, and doubly numerous ; it is also gene- 

 rally a much smaller, and less common species : the spire is 

 always deeply tinged with pink. The genus Padollus, of 

 Montford, resting entirely in the unevenness of the outer lip, 

 without any knowledge of the animal, appears to me an un- 

 necessary distinction, for such is the character of all young 

 shells, and also of mature ones, whose outer surface is rugged 

 or uneven. 



PI. 80. 



