— 599 — 
more nearly flat, and often proportionally broader, and the pun- 
ctiform scars are frequently near the middle of the elevation instead 
of near the prominent apex as in most of the tubercles both large 
and small. 
The portion of cuticle included in Fig. 8, just described, is huta 
part ofa rather lax oblong fragment that reaches the border of the 
lamina at one end only. When near the border the tubercles rapidly 
increase in size and number so as to give a scaly appearance. 
This narrow zone of scale-like tubercles, which corresponds exactly 
to that next to the free border in the original of Pl x, Fig. 4, is im- 
mediately succeeded by a row of large tuberculate scales or marginal 
teeth, Pl. xi, Fig. 10, about 2 mm in lenght, a little more in with, 
round obtuse at the apex and separated by rounded sinuses. These 
scales are exactly like those shown on the small fragment to the right 
in Fig. 8, Pl. x 
Another fragment with slightly smaller and more narrowly 
rounded marginal scaJes is seen four times enlarged in Pl. xi, Fig. 7. 
The granulose cuticular surface extending even to the bases of the 
scales is identical with that shown in a portion of Fig. 3, which is 
equally enlarged. Where this cuticle is removed from portions of two 
of the teeth on the right, the finely tubercular impression of the oppo- 
site side of the fossil is seen. 
This feature, still better shown in Fig. 8, equally enlarged, seems 
to indicate an extension of the smaller tubercles out on the lobe or 
tooth-tubercle on that side of the lamina. The fragment seen four 
times enlarged in Fig. 6, exhibits unusually large marginal tooth 
scales two of which appear tobe in the process of fission at the apex. 
It may be of interest to note that these teeth are at the border of 
an area of granular and small-tuberculate or «convex » cuticle, a 
portion of which is overlain hy a fragment of the « convex » or large- 
berculate cuticle. 
A filling of matrix (cast) nearly 1.5 mm in thickness separates 
the two cuticles. That both cuticles belong to the same individual 
is indicated by the parallel position and the orientation of the large 
tubercles and the scales. 
One of the most interesting specimens in the series is that shown 
in natural size, Pl. xi, Fig. 2, and in part photographically enlarged 
in Five 2a. 
