Historical Account of Testaceological Writers. 121 
With respect to the general execution of our task, it is incumbent 
on us to solicit the indulgence of this learned Society, by whom 
we hope those deficiencies will be pardoned which have not pro- 
ceeded from neglect of means of information within our reach. 
ARISTOTLE, 
the illustrious father of system in general, seems to have been 
also the first writer, and the inventor of method, in Tcstaccology. 
In his History of Animals (book iv. ch. 4.) we find a copious de- 
scription of that tribe to which he has affixed the term Orgotxoisgpoi, 
a term apparently intended to include all such animals as are con- 
tained in a shelly covering. It is remarkable enough, that the very 
first attempt to reduce the species of this tribe under a regular 
system was so far successful that its outline stood the test of sub- 
sequent discoveries, and was retained in Testaceology to a late 
period. It was Aristotle who formed the divisions of 
1. Univalves, 
2. Bivalves, and 
3. Turbinated Shells; 
and the terms which he applied to several subdivisions, or genera, 
remain, as well as the genera themselves, in all modern systems. 
The terms Lepas, Solen, Pinna, and Nerita, may serve as exam- 
ples. Of the animals themselves, distinctly from the shells, this 
philosopher (as might naturally be supposed) possessed but a 
very imperfect knowledge; yet he saw the necessity of connect- 
ing the structure and habits of them, as far as was possible, with 
the form of their coverings, in the framing of a scientific system. 
Thus, in hh genera of Cocalia, Purpurce, and Buccina, lie expressly 
describes the head and flesh of the included reptiles. Aristotle's 
merit, however, was only that of having established some philo- 
sophical and permanent distinctions. The number of shells known 
vol. vii. r in 
