ON MOLLUSCGA. ots 
Methodica ratione instituendis, in which we find but few im- 
portant innovations. He paid, especially in the univalves, more 
attention to the spire than perhaps had been given before his 
time; and in the bivalves, his first division is founded:on the 
presence or absence of a hinge. 
In 1742, Gualtieri, an Italian author, whose work is still 
often cited, from the great number of mediocre figures which 
it contains, published a method, in which he has employed all 
the combinations which his predecessors made use of, without 
introducing any thing new. Thus his first division equally 
rests on the habitation of the shells. He names exothalassi- 
bie those which are not marine, and divides them as usual 
into fluviatile and terrestrial: as to the marine, thalas- 
sibie, they are turbinated or not, and the latter are vascular 
or tubular; he admits the polythalami. He pays atten- 
tion to the equality or inequality of the valves, and of their 
sides. Finally, he considers the presence or absence of the 
hinge. In general, though in this work we find a considera- 
ble number of generic sections indicated, they are not solidly 
established. 
In the same year was published, in France, the first edition 
of a work, which for a long time enjoyed a degree of reputa- 
tion which it little merited. It was by d’Argenville, entitled 
U Histoire Naturelle eclaircie dans deux de ses parties prin- 
cipales, la Lithologie, et la Conchyliologie, in 4to. Although 
this work was very successful, especially in France, in conse- 
quence of the figures which it contains, its merit is of a very 
inferior order. In fact, the author has introduced absolutely 
no new consideration in the manner of observing shells, which 
he again divides, according to their habitation, into marine 
and fluviatile, but nevertheless places the helices among 
the latter. Each section or subdivision is divided, according 
to the number of pieces, into univalves, bivalves, and multi- 
valves, for the first, and into univalves and bivalves only for 
VOL. XII. T 
