6 CONCHOLOGIST’S COMPANION. 
to present a constant succession of rich and changeable 
colours, that— 
Flying several from each surface, form 
A trembling variance of revolving hues, 
As the site varies in the gazer’s hand. 
Thomson. 
4 
Nature, always magnificent in her designs, but 
singularly frugal in the execution of them, produces 
these brilliant decorations at a small expense. The 
membranaceous substance is plaited and rumpled in 
such a manner, that its interior lamine, being in- 
crusted with earthy and semi-transparent matter, form 
an infinite number of little prisms, which refract the 
rays of light, and produce all the changes of colour 
observable in these brilliant shells. 
Oh! who that has an eye to see,— 
A heart to feel,—a tongue to bless, 
Can ever undelighted be 
By Nature’s magic loveliness ! 
The most beautiful shells are generally brought 
from the Red Sea and East-Indies. Those of the 
West are less brilliantly tinted; and as we advance 
towards the temperate and arctic regions, they 
gradually diminish in lustre and variety, till at length 
a few solitary specimens of the genera Trochus, 
Buccinum, and Limpet, are occasionally found on the 
