178 PALEOZOIC FISHES OF NORTH AMERICA, 
This species resembles C. acutus and C. mirabilis, Ag.,’ but differs 
from both in having the interior pair of secondary cones as large as the 
outer pair, or even larger; in this respect it is unlike any other species 
known to me except C. Hertzeri.’ 
C. Romingeri was briefly described in the Paleontology of Ohio, but no 
figure was there given of it. 
Formation and locality: Waverly sandstone; Battle Creek, Mich. Col- 
lected by Dr. Charles Rominger, to whom it is dedicated. 
MAZODUS, nov. gen. 
Teeth of Elasmobranch fishes often of large size, thick and massive, 
with an ovoid, elliptical, or angular outline; upper surface arched in both 
directions, smooth or finely granulated; under surface concave, coarsely 
pitted, and variously furrowed and lobed; sides marked by irregular, often 
pustulous ridges; interior similar throughout, showing irregular, vertical, 
calcigerous tubes or columns closely compacted into a dense, hard, and 
enamel-like tissue. 
The objects which form the basis of the above description are peculiar 
and their nature and functions are somewhat problematical. These speci- 
mens, from the Waverly of Ohio, evidently belong to a group which includes 
the so-called teeth of Helodus rudis of Agassiz and McCoy, and the peculiar 
specimen called Petrodus ? pustulosus,* N. & W. They all present some char- 
acters which are not found in other fish teeth, and which at one time led me 
to consider them as dermal ossicles, viz: First, the arched upper surface is 
granulated or pitted in quite a different way from that of the teeth of Psam- 
modus and all allied genera. Second, they are composed of dense enamel- 
like tissue throughout, with no division into crown and base, one enamel 
and the other bone, such as we find in all known crushing teeth of Elasmo- 
branch fishes. Third, the sloping sides are marked with irregular, often 
tuberculated ridges, which are absent from the borders of all other unmis- 
takable fish teeth, and which closely resemble the markings on the sides 
1 Poissons Fossiles, vol. 3, pp. 197, 199, pl. 22, figs. 9, 12-21. 
2 Paleontology of Ohio, vol. 2, p. 46, pl. 57, figs 5, 5°. 
3 Geol. Survey Illinois, vol. 4, p. 369, pl. 2, figs. 5, 54, pl. 3, fig. 6. 
