A New Genus of Silurian Fishes. 
73 
the surface of the calcareous plates of Pteraspis. If his 
reasoning is correct, the plates of the Acadian fish were also 
probably clothed with a similar covering. 
These fish remains were taken from beds of the Silurian 
‘System which are found on the southern slope of the Nerepis 
Hills, in Kings County, New Brunswick. The beds are of very 
fine texture, being evenly banded, silicious mud rocks or hard- 
ened shales. They are similar in aspect to the strata of No. 2 
in the Silurian Succession at Passamaquoddy Bay in Charlotte 
County. No. 3 contains in that neighbourhood a marine 
fauna similar to that of the Lower Helderburg Formation 
{equivalent to the Ludlow of England). These fish remains 
would therefore seem to be as old as the oldest known in 
Great Britain, though perhaps not quite so old as some found 
in Pennsylvania by Prof. Claypole. 
The beds from which the Acadian fish was taken abound 
with carapaces of a small species of Ceratiocaris , and also con- 
tain the remains of a limuloid crustacean allied to Hemiaspis. 
The genera of Pteraspidian fishes known to the writer are 
the following: — * 
Palceaspis (Claypole) Scutum simplex, ovale f — Silurian. 
Scaphasis (Lankester) Scutum simplex, ovale — Silurian and Devonian. 
Cyathaspis (Lankester) Scutum in quatuor partes divisum ovale — 
Silurian. 
Diplaspis (nov. gen.) Scuta in dorsum et pectorem, in septem (?) 
partes divisa, o valia— Silurian, 
Pteraspis (Kner) Scutum in septem partes divisum, sagittiforme — 
Devonian. 
* The diagnoses of the second, third and fifth genera are taken from Prof. 
Lankester’s Memoir, cited. 
t See footnote opposite. 
