156 
Dr. Maton's and Mr. Rackett's 
the title of Historic SimpUcium. The testaceological remarks are 
extremely superficial, and defective in originality, 
RICHARD BRADLEY, 
though not a professed testaceologist, has not altogether omitted 
this order of animals in his " Philosophical Account of the Works 
of Nature;" and his figures of the species, though few and scat- 
tered, are not unworthy of being referred to. This work in its 
day must have been considered as an interesting view of the 
ceconomy of nature, being judiciously written, and illustrated by 
a considerable number of accurate engravings. 
Hitherto system in testaceology had made but little progress. 
That of Buonanni was almost the only one which can be said to 
have been fully and philosophically exemplified, and its outline 
was more or less preserved in most succeeding attempts ; but its 
defects and errors, as we have before remarked, were numerous. 
After having noticed a multitude of mere describers, we now 
come to an author who- is not undeserving of the title of a scien- 
tific one, and whose system, so far as marine Testacea are con- 
cerned (and of these alone he treats), certainly glances at the 
great clue to simplicity, which was afterwards so successfully and 
admirably seized by the great reformer of natural history in ge- 
neral. The author alluded to is 
LANGIUS. 
He is the first whose generic characters are founded on com- 
modious distinctions, the aperture of univalves, and the hinge of 
bivalves, being particularly considered. These distinctions, how- 
ever, are not allowed their due importance throughout; for the 
contour of the shell is, in many instances, made the exclusive 
basis of the definition, and the adoption of this naturally led, as 
in 
