102 HAY—VERTEBRATES OF CARBONIFEROUS AGE. [March 16, 
Megalichthys occidentalis, Hay, O. P., Amer. Naturalist, xxxiii, 
1899, p. 787. 
Sagenodus brownie, Cope, E. D., Proc. AMER. PuiLos. Soc., 
XXXVi, 1897, p. 81, Pl. i, Fig. 7; Williston, S. W.; Kansas 
Univ. Quart., viii, 1899, p. 177. 
This species was briefly described by Newberry and Worthen in 
1866, as above cited, and was illustrated by a wood-cut. This 
presented the general characteristics of the scale, but did not show 
well the system of nutrient canals. ‘The same author’s figure of 
the species published in 1870 also failed to show adequately the 
canals. In Prof. Cope’s posthumous paper of 1897 the species was 
first referred to Sagenodus. 
In his synopsis of the species of the genus, on page 76, he says of 
SS. occidentalis, ‘‘ Concentric lines conspicuous ; tessellations and 
radii not conspicuous.’’ By ‘‘ tessellations’’ was meant the areas 
formed by the network of canals, and by ‘‘ radii’’ the excessively 
fine lines which radiate from the central part of the scale toward 
the free border. However, the conspicuousness both of the canals 
and of the radiating lines depends much on the character of the 
fossilization, one or the other being often effaced. This must be 
taken into account in considering the species. I have before me 
a specimen (Daniels’ No. 13) which has a great resemblance to 
Newberry and Worthen’s original figure. It is, however, propor- 
tionately longer, its width being nearly equal to its length, while 
the figure referred to is somewhat wider than long. ‘The scale is 
also smaller than that figured by Newberry and Worthen, the 
length being 33 mm. There is a border of conspicuous concentric 
lines, and the free border is minutely striated. But there is also a 
very conspicuous system of nutrient canals. ‘This system consists 
of one set which start from the centre of growth of the scale and 
radiate, some toward the attached border of the scale, others 
toward the free border. An upper area of the scale is occupied by 
similar canals, which, starting at the upper extremity of the 
attached border, pass somewhat toward the centre; then, turning 
again backward and upward, come out on the upper side of the 
free border. A lower area of the scale is similarly marked. A 
second set of canals runs approximately at right angles to the set 
just described and unites them, thus dividing the scale into little 
areas which are more or less regular parallelograms. In another 
specimen (Daniels’ No. 12) the centre of growth of the scale is 
