1538 
between the extremities of the mandibles, apparently acting 
as the prow of a ram. 
Another bucklered fish he called Aspidophorus, or the shield 
bearer, because the central plate of the thoracic buckler was 
thirteen by seventeen inches in dimensions, more than an 
inch in thickness in the centre, and studded all over with 
enameled tubercles as large as half peas. The affinities of 
this fish were apparently with Pterichthys, but it was a hun- 
dred times as large. Its remains were found in the Huron 
shale, just over the Corniferous at Delaware, Ohio. 
The hugest of all these old fishes, he had named Dinichthys 
or terrible fish. In this the head was three feet long by two 
in width, the under jaws more than two feet in length, an 
inch and a half thick at the thickest part, and five or six 
inches in depth. These turned up anteriorly like sled 
runners, their extremities forming great triangular teeth, 
which interlocked with equally huge teeth from the upper 
jaw. The middle dorsal shield of Dinichthys was some six- 
teen inches in diameter. 
Rhynchodus was the name proposed for a new genus, 
represented in the collection by two kinds of tecth. These 
are semicircular in form, from three to five inches in diameter, 
very strong and massive. They apparently formed a beak- 
like rostrum. In one species the teeth of the opposite jaws 
played on each other like the blades of shears, and the 
specimens exhibited were so worn as to present sharp cutting 
edges along the upper margin. The teeth of other species 
are thicker and more massive and evidently fitted for crushing, 
rather than cutting. 
These teeth Dr. Newberry considered as belonging to 
Chimerovd fishes. 
A new species of bucklered fish, now first brought to 
notice, he called Acanthaspis or spiny shield. In this, the 
buckler terminated laterally in strong defensive spines, like 
those worn on the backs of sharks. 
