^TITES, OR EAGLE-STONE. 
611 
harder. In a piece of this stone, of the size of a finger, it is com- 
mon to find thirty or more of these fossils ; and often they are seen 
in form of white specks, so minute that their figure cannot be distin- 
guished till examined by the. microscope. They all consist of several 
volutae, which are different in the different species, — and their striae 
also are extremely various ; some very deep, with very high ridges 
between them, others very slight; some straight, others crooked, 
others undulated ; and some terminating in dots, tubercles, or cavities, 
towards the back, and others having tubercles in two or three places. 
They are composed of a great number of chambers or cells, in the 
manner of the nautilus Graecorum, each having a communication with 
the others by means of a pipe or siphunculus. 
There is a small white shell-fish of Barbadoes, which seems truly a 
recent animakof this genus ; and, in the East Indies, there is another 
also, small and greyish ; but the large and beautifully marked ones 
are found only fossil. They are composed of various fossil bodies, 
often of quarry stone, sometimes of the matter of the common pyrites, 
and of a great variety of other substances ; and though they appear 
usually mere stones, yet in some the early part of the original shell 
is perserved in all its beauty. Sometimes also, while the outer sub- 
stance is of the matter of the pyrites, or other coarse, stony, or mine- 
ral matter, the inner cavity is filled with a pure white spar of the 
common plated texture. This gives a great beauty to the specimen. The 
cofnua-ammonis, or snake stones, are found in many parts of England, 
particularly in Yorkshire, where they are very plentiful in the alum 
rocks, of several sizes. 
JEtites, or Eagle Stone. 
This is a curiosity in natural history, which was formerly in repute 
for several extraordinary magical as well as medical powers ; such 
as preventing abortion, discovering thieves, and other ridiculous pro- 
perties. The popular tradition is, that it is found in the eagle’s nest, 
whither it is supposed to be carried while the female sits, to prevent 
her eggs from being rotten. These stones are found in several parts ; 
near Trevoux in France, one can scarce dig a few feet deep, without 
finding considerable strata, of a coarse or ferruginous kind. They are 
originally soft, and of the colour of yellow ochre. But the finest and most 
valued of all the eagle-stones, are accidental states of one or other of our 
common pebbles. These are so far from being a peculiar species of 
fossil, though usually accounted such, that they are not determinately 
of any one species of pebble. Those, however, which most usually 
furnish them, are the brown centered pebbles, with whitish, bluish, and 
brown crusts. 
The plain history of this remarkable fossil is this : the central nucleus 
of many species of pebbles, particularly of this, is coarser than the 
rest of the stone, that is, it is made up of more earth and less crystal; 
the natural eonsequence of which must be, that being of a more loose 
and rare texture, it is in drying more apt to shrink than such masses 
as are composed- of a harder and purer matter. The central nucleus 
in this species is also surrounded with a whitish crust, of a more loose 
