SHELLS WITHOUT A REGULAR SPIRE. 59 



Genus S].—RALIOTlS. 



Animal a Limax; shell ear-shaped ; univalve and dilated, 

 with a longitudinal row of orifices opening on the surface; 

 spire lateral, and nearly concealed. 



The animals composing the sheUs of the genus Haliotis, inhabit the 

 sea only. They adhere closely to rocks, and can only be removed by 

 suddenly snatching them from their hold. In some places the animal 

 is esteemed good eating. One species, the Hahotis tuberculata, is very 

 common in Guernsey, and sold in the market as food. 



Haliotis tuberculata The Tubercular Haliotis 



Plate IX. fig. 31. Dull reddish brown on the outside, 

 sometimes clouded or mottled with a deeper shade : longi- 

 tudinally striated, and transversely wrinkled, with a few 

 raised tubercles; inside periaceous, reflecting the most beau- 

 tiful shades of pink, blue, green, and yellow ; aperture open 

 the whole length of the shell, outer-lip irregular. From 

 three to four inches long. Inhabits the sea at Guernsey. 



It is asserted, that as a new hole is added by the animal to the sheU, 

 it carefully closes up the next open one to the spire ; by which means 

 the number of orifices is, in general, the same in all shells of one 

 species. 



DIVISION SECOND.— SHELLS WITHOUT A REGULAR SPIRE. 



Genus S-2 PATELLA. 



Animal a Limax ; shell univalve, subconic, shaped like a 

 bason ; without a spire. 



Linnaeus divides this genus into five families : *fumished with an in- 

 teraal hp ; shell entire ; **with the margin angular or in-egularly 

 toothed ; ***i\-ith a pointed recurved tip or crown ; **«*very entire, 

 and not pointed at the tip or vertex ; *****with the crown perforated. 



Patella vulyata — The Cobimon Patella. Plate IX. 

 fig. 32. Subject to great external variety ; ribbed from the 

 vertex to the margin in some specimens, and with divergent 

 striae; others striated merely, without ribs; of a dark brown 

 or olive green on the outside, and the inside blue, shining 

 with deep purple radiations; and presenting a great variety 



