woodward: fossil fishes of the upper lias of WHITBY. 471 
collection in the Malton 
Museum ; while a few 
specimens from a very 
large tail are to be seen 
in the York Museum. 
The scutes are bilaterally 
symmetrical, flattened, and 
taper to an acute apex ; 
they are destitute of an 
external layer of enamel, 
and the only traces of 
ornamentation are feeble 
rugie on the exposed sides. 
The largest specimens at 
York measure about 0 • 1 2 m. 
from the apex to the bi- 
furcation at the base. 
So far as can be 
judged from the foregoing 
description, the only 
definitely known character 
by w^hich Gyrosteus is 
distinctly separated from 
Chondrosteus is afforded 
by the shape of the 
maxilla. It is therefore 
of interest to append 
a restored figure of 
C. acipenseroides (fig. 13), 
founded on nearly com- 
plete skeletons from the 
Lower Lias of Lyme Regis. 
On this basis it seems 
possible to estimate the 
approximate length of the 
largest individuals of 
