162 Objects for the Microscope. 



with minutely serrated edges making a powerful instru- 

 ment for rasping the surface of the sea-weed upon which 

 the Trochus feeds. 



The mouth (of the Trochus) has no upper horny plate, 

 and therefore probably needed this elaborately toothed 

 tongue. 



PALATE OF TROCHUS CRASSUS. 



Trochus Crassits is a variety of the same family, having 

 a large gray shell, and the tongue less beautiful. 



PALATE OF TROCHUS UMBIL1CATUS. 



Trochus umbilicatus; a smaller and more abundant shell, 

 also of gray colour. 



PALATE OF PERIWINKLE. 



(Littorina.) 



The Periwinkle is too well known to need description, 

 and the palate is very like that of the Irochus Crassus. 



PALATE OF HALIOTIS, OR AUMER. 



The Haliotis is that beautiful univalve mollusc found in 

 the Channel Islands, under stones at low tide ; the fleshy 

 foot is sold in the market there, and highly esteemed as an 

 article of food, either stewed or fried in batter. The shell 

 is brought to England, and sold to manufacturers of works 

 inlaid with so-called mother-of-pearl, which is really the 

 beautiful interior of this shell. The palate is one of the 

 finest prepared for the miscroscope, and yet more compli- 

 cated than that of Trochus ziziphinus, which it resembles. 

 The central band here has rows of teeth, having nearly 

 straight edges instead of points ; there is on each side a 

 lateral band consisting of large teeth, shaped like those of 

 a shark ; and beyond this, again, another lateral band on 

 either side, composed of several rows of smaller teeth. (See 

 1 Carpenter on the Microscope/ p. 605.) 



The Haliotes are carnivorous as well as vegetarian, often 

 found feeding on dead bodies. 



