766 THE AMERICAN NATURALIST. [VOL. XXXII. 
median carina. Its slender terminal process must also have 
been broken off before he saw the specimen. 
cerry e =: 
k 
> 
1G. 5. — Titanichthys clakrii Newb. Cleveland Shale, Ohio. Dorso-median plate, lacking 
median anterior spine and cranial process. (Reduced from a figure by Newberry.) X st. 
pL en MLTR 
Fic. 6. — Cleveland Shale, Lorain County, Ohio. Visceral aspect of dorso- 
jedik belon aging  reamabl to an immature individual. Original in Oberlin Museum. 
Very nearly natural siz 
The chief peculiarity of this plate is the deep indentation 
of its lateral margins, but this is to be regarded merely as a 
