284 THE MEDALS OF CREATION. Cuap. VII. 
and ornament, the same general type of structure prevails — 
throughout the family. 
Fossin STEMS AND OssicuLa oF CrinompEa. — (Bd. pl 
xlix.—lii. Pict. Atlas, pl. xlvii.)—The detached ossicula and — 
stems are so common in many places, that they attracted — 
the notice of the earlier collectors, by whom the single 
pieces were termed trochites (wheel-stones), and the united — 
Lien. 90. STEMS OF ENCRINITES AND PENTACRINITES. 
Fig. 1.—Screw or Pulley-stone. Derbyshire. 
2, 4.—Articulating surfaces of Encrinital ossicula. 
3, 5.—Entrochites, or portions of stems of Encrinites. 
6, 8, 10.—Portions of Pentacrinital stems. 
7, 9.—Articulating surfaces of ossicula of Pentacrinites. 
series entrochites. In the north of England these fossils are 
called Fairy-stones, and the circular perforated ossicula 
Saint Cuthbert’s beads ; the latter were worn as ornaments 
by the ancient Britons, and are occasionally found in tumuli. 
These petrifactions present considerable variety in form, 
and in the markings on their articulating surfaces, which 
