1879. | Columbia College. 507 
were strongly united by sutures and highly ornamented on the ex- 
posed surfaces. This fish, which has received the long name of 
Macropetalichthys, seems to have had many features in common 
with the structure of the living sturgeon. One of the strangest 
fishes that ever swam in the Devonian seas, and which surpasses in 
interest even the Prerichthys and Coccosteus of the old world, is the 
Onychodus. Among the most unique specimens in the museum 
is a slab of limestone from the Corniferous rocks of Ohio, con- 
taining a nearly perfect mandible of this fish, which is fourteen 
inches in length and set with sharp conical teeth. At the junc- 
tion of the two rami of the lower jaw, there occurs a crest of seven 
large curved teeth which seem to have projected beyond the mas- 
sive jaws, thus forming a terrible weapon, whose use seems to 
have been analogous to that of the sword in the living sword-fish. 
Far more wonderful than any of these, and one of the strangest 
monsters ever exhumed from the cemeteries of the primeval 
world, is the Dinichihys, described by Prof. Newberry from the 
Huron shales of Ohio. The nearly perfect bony casing of this “ ter- 
rible fish,” which is exhibited, shows it to have been upwards of 
twenty feet in length; and judging from its formidable armament, 
it was by far the most destructive creature yet known from the 
© Devonian rocks. The jaws are massive plates of dense bone, 
each two feet in length, and provided with sharp-cutting and ser- 
rated edges. The anterior ends of the mandibles are upturned 
and united so as to form one immense tusk-like tooth, which 
shuts in between two equally massive premaxillaries on the upper 
jaw. The jaws of Dinichthys may be well represented by the 
arms of a man extended to their full length with the hands 
turned up and pressed together to represent the great tooth at 
the junction of the mandibles. One of the most curious and 
interesting features connected,with this discovery is the striking 
analogy that exists between the structure of the Dinichthys and 
the mud-fish (Lepidosiren) now living in the rivers of Africa 
and South America. The number of these Devonian fishes is so 
great that we can but glance at a few of the more interesting ones 
that remain. Beside the dorsal shield of Coccosteus from the Old 
Red Sandstone of Scotland, is placed the only similar specimen 
known of Coccosteus from this country. Here too is the type- 
Specimen of the genus Heliodus, one of the most ancient of the 
Dipnoi. Specimens of Rhynchodus show us that the modern | 
Chimzra belongs to a very ancient family. 
VOL. XIII,—no, VIII, “oo 
