Historical Account of Tcstaceological Writers. 193 



ccpting Lister, and his information is (on this subject at least) in 

 no respect ample. 



In tne Fundamenta Zoologica of 



BRUNNICH 



we find a few genera added to those of Linnaeus, but only among 

 the univalves; the genus Nautilus being divided into three, and 

 that of Buccinuin into the same number. These alterations are 

 strictly reconcilable with Linnean principles, yet it may be rea- 

 sonably doubted how far they are necessary. 



At the head of those writers who have contended for what may 

 be called the natural system of Testaceology, or a system founded 

 on the stucture and habits of the inhabitants of shells, may be 

 placed 



OTHO FREDERIC MULLER, 

 one of the most laborious and sagacious zoologists of his age. In 

 his " Vcrmium terrestrium etfluviatilium Historia" we have a sketch 

 of his proposed arrangement of the land and river Ttstacea, which) 

 according to this author, form two very distinct orders, though 

 not differing from each other so widely as the fresh-water and 

 the maritime. The characters of his genera are taken chiefly 

 from the shape of the tentacula of the animals; in the bivalves, 

 from the siphon which they protrude. Hence the Linnean genus 

 Limax is included in the testaceous instead of the molluscous 

 order. The work in which these outlines are given is published 

 in two volumes, the first begun in 1773, and the second in 1774: 

 the latter relates solely to the subject of which we are treating ; 

 and its preliminary matter, in a physiological and anatomical 

 point of view, is of a very curious and instructive nature. 



In 1 7?G our author printed a Prodromus of the Zoology of Den- 

 mark, containing concise descriptions of every known species in- 



vol. vu. 2c habiting 



