marine Dritish Shells and Animals. 193 
the Linnean 4nomie with the beak of the superior valve per- 
forated. | 
So little are we acquainted with the animal inhabitants of the 
greater part of Testacea, that it has been usual to follow Lin- 
næus in assigning to each genus of shells, as arranged by him, 
animals of a similar nature; but later observations have proved 
that nothing can be mote distinct than many of the animals 
which inhabit shells of the same family under the Linnean ar- 
rangement. The animals of the Linnean Anomie are as different 
as the shells, and do not correspond with the general characters 
assigned to the genus: in fact, the animal appears to be so 
indefinable, that no name has been given to it. 
— Lamanon gives a long description of the animal of a species of 
Terebratula which was found on the coast of Tartary by the unfor- 
tunate Peyrouse, in his voyage of discovery, in which he observed 
several bones (testaceous plates) that support the ears (the mem- 
branaceous rays or fins ?). This writer speaks of the syphon or 
tube merely as a pedicle or foot of adhesion, not having seen it 
in the light of a mouth, through which all nourishment is taken, 
(as in the greater part of the Vermes found to inhabit bivalve 
shells,) but speaks of a mouth with a transverse opening, which 
is ill defined, and I have little doubt he was mistaken. The 
great powers of adhesion ascribed to the tube of this animal can 
only be in proportion to the diameter of the cup of the tube, in 
which a vacuum is formed, which cannot exceed two lines: the 
philosophical naturalist may therefore judge of the extent of the 
adhesive power these animals possess. The shell of this Tartarian 
species appears to be in many respects allied to the Terebratula 
Cranium in the hinge, and processes thereto attached, but exter- 
nally is much more wrinkled : besides, it is thick, and somewhat 
different in colour. This appears also to be essentially different 
from 
