Three Xnr Specie* of Dinichthys. — Claypole. 'Ill 
The tuberculated surface of this tooth is its main feature, 
so far as its definition is concerned. No other Dinichthys is 
known in which such a character occurs. At the same time 
there may be noted a certain resemblance between it and the 
premaxillary of I), hertzefi, of the Huron shale, in that the 
latter possesses a row of denticles on its edge analogous to some 
of the tubercles of the present species. As the two must be 
considered almost contemporaneous, this may be an indication 
of relationship. 
The super-scapula and the dorso-median of I), tuberculatum 
from Warren, Pa., also show a similar tuberculated ornamen- 
tation, but nothing more is known of that species. It is, how- 
ever, from the Chemung, whereas the form here described was 
found in the Marcellus shale. 
I propose to put upon this species the name of its discov- 
erer, Dr. D. F. Lincoln, of Geneva. X. Y., and to call it Din- 
ichthys lincolni. 
I am indebted to Dr. Lincoln for calling my attention to 
the fossil, and to Prof. J. M. Clarke, of Albany, for the loan 
of the specimen from the State collection and permission to 
describe it. I am also indebted to the latter gentleman for 
the opportunity of adding to this article the following ex- 
tract from what was. in all probability, the last, or almost the 
last, letter on his favorite subject that was penned by the 
late Dr. Newberry, through another hand, after he had been 
struck down by the attack which caused his death some 
months afterwards: 
Prof. J. M. Clarke. 
My Dear Sir: I received the fossil from the Marcellus shale which 
you sent me, in due time, but just about then I was arrested in mid- 
career by a partial paralysis of my right side. I have been slowly re- 
covering since, and, should no accident occur, shall be able to resume 
my duties and studies within a few months. 
I have delayed writing you about the fossil until I should return 
to New York and look over some fossils from the Marcellus which I 
have there. I am about starting, however, on a health-trip to the 
South and shall not be able to do that before I go. I therefore return 
the specimen with the following notes: 
It appears to be the premaxillary of a species of Diniclithys or of an 
allied genus which is characterized by a very coarse and smooth tuber- 
culation of its external bone surface. I have some bones with the 
same ornamentation from the Marcellus at Schoharie, but they are too 
imperfect for description. 
