16 
POPULAR SCIENCE REVIEW. 
Closely allied to Agassiz’s genus Coccosteus — if not probably 
identical with the great Cromarty fish discovered by Hugh 
Miller, but of far more gigantic proportions — is the great Placo- 
derm described by Professor Newberry* from the Upper Devonian 
Black Shales of Delaware, Ohio. 
This enormous armour-plated fish, for which the name 
Dinichthys has been proposed, deserves the same distinction 
among fishes as the Dinosaurians among Reptiles, and the 
Dinornis among birds. 
Fig. 14. 
1. anterior aspect of head of Dinichthys Herzeri (^th natural size). 
2. mandible of same (£th natural size). 
Most of the bones obtained belonged to the head, which was 
about three feet in breadth and nearly three inches in thickness, 
being strengthened at the occiput with internal ridges. The jaws 
were° each two feet in length. The external surface of the bony 
plates is ornamented with very fine vermicular markings. The 
body is estimated to have been about 15 feet in length. 
The anterior part was protected, as in Coccosteus , by huge 
dorsal and ventral shields ; and from the absence of scries, it 
* State Reports, u Palaeontology of Ohio,” Vol. ii. xl Geol. Mag.” 1868, 
Yol. v. p. 184, and 1877, Decade ii. Vol. iv. p. 213. 
