
CARBONIFEROUS CONODONTS OF WEST OF SCOTLAND. 339 
presents as smooth, polished, and lustrous an appearance as if they 
had been derived from some existing animal, and no one would 
suppose from their appearance that they dated from the long-past 
ages of the Carboniferous epoch. In some examples the minute 
denticles are more or less fractured, but this might readily happen 
even in recent objects of similar delicate structure [the frac- 
turing is in most cases evidently recent], but in other specimens 
the teeth are as sharply pointed and their lateral edges as acute 
as if they had but recently been fulfilling their functions. They 
excel in their state of preservation those occurring in the Ameri- 
can rocks, which are for the most part imbedded in shale or lime- 
stone, and but seldom met with free from the matrix, whereas 
these Scotch examples are perfectly free from matrix, and thus 
allow their forms to be much better determined. In composition 
and structure they appear to be identical with the American and 
Russian forms, and present a light-brown, translucent, horny 
aspect. One or two specimens are white and opaque, a difference 
owing probably to chemical change from exposure. There is 
equally as great a variety in the form of these Scotch Conodonts 
as in those from America and Russia, and, while many examples 
are identical with specimens which are common to these widely 
separated localities, there are other specimens which vary in 
detail from any which have yet been figured. Those latter I have 
indicated below by new names, though I by no means wish to 
assert that they are to be regarded as distinct species. Our 
present ignorance of the character of the animals to which these 
teeth belonged makes it a matter of conjecture as to the value to: 
be attached to differences in their form ; and the discovery which 
I made of numerous different forms of small teeth and plates 
associated together, so as to lead to the belief that they belonged 
to a single individual, renders it highly probable that, notwith- 
standing the great variety of form of these minute bodies, they 
may represent but a few species. In the meanwhile, however, it 
very desirable to ascertain and figure these different varieties, 
and until some happy discovery shall enlighten us respecting 
their relations to each other it will be convenient to give to each 
of them a distinctive appellation. 
No fresh discovery either of fossil or recent forms of life has 
been made which would tend to clear up the doubts whether the 
