34 MOLLUSCA. 
to perfection the artificial system of conchology, and have 
formed their arbitrary characters, independent of the habits 
of life of the contained animal. But the naturalists whom 
we have now to consider, have traced these animals to their 
lurking places, and arranged them according to the situation 
in which they reside, instead of the forms which they ex- 
hibit. 
At the head of this class of conchologists, Dr. Martin Lis- 
ter stands pre-eminently conspicuous. His great work, en- 
titled Historia sive Synopsis Methodica Conchyliorum, was 
begun in 1685, and completed in 1692. It will long remain 
a monument of the extensive information and unwearied 
diligence of its author. The following synoptical view of 
the work will enable our readers to comprehend its plan; the 
original should be consulted with care. 
Lib. i. De Cochleis terrestribus. 
Pars 1. De Buccinis terrestribus. 
Pars 2. Cochleze nudz terrestres Limaces quibusdam 
dictee. 
Lib. ii. De Turbinibus et bivalvibus aque dulcis. 
Pars 1. De Turbinibus. 
Pars 2. De Testaceis bivalvibus fluviatilibus. 
Lib. iii. De Testaceis bivalvibus marinis. 
Pars 1. De Testaceis bivalvibus, imparibus testis. 
Pars 2. De Testaceis bivalvibus, paribus testis. 
Pars 3. De Testaceis multivalvibus. 
Lib. iv. De Buccinis marinis, quibus etiam vermiculi, 
dentalia et patella numerantur. 
The plan followed by Sir Robert Sibbald in his Scotza 
Illustrata is somewhat different from that of Lister. He 
divides the Testacea into two classes, land and water shells, 
and the latter class he subdivides into fluviatile and marine. 
