
6 
shall certainly not feel myself compelled to make 
any such restitution. The day of publication can 
alone decide a question of this kind, else a natu- 
ralist might describe fifty species at random, read 
them at a meeting of some scientific institution, 
and then cull out at his leisure a half dozen new 
ones, and claim them as his own six years after- 
wards, although perhaps they had been published 
under other names, five years before his descriptions 
‘appeared. Other reasons could be given, but it is 
unnecessary to multiply them in so plain a case. I 
will, however, observe, that a naturalist lately read 
descriptions of two hundred new species, and when 
his descriptions were published, they amounted to 
two hundred and fifty—how can any. one distinguish 
the interpolations? 
The great variety and beauty of the fresh water 
shells of this country are truly surprising. Whilst 
the streams of Kurope contain very. few species, not 
remarkable for elegance of colour or variety of form, 
the rivers of Ohio, Kentucky, Tennessee, Alabama, 
- &e. contain at least one hundred species of almost 
every imaginable shape. Many of these are richly 
coloured and ornamented with rays, tubercles and 
undulations, and some equal in lustre the habitation 
of the oriental pearl, To these beautiful and multi- 
Sem shells, the few less ornamental apecios of the 

