W. B. Dwight—Fossils of the Wappinger Valley. 253 
and two tubercles situated close together at its posterior termi- 
nus. The lateral lobes are less convex than the axial, and 
marked by three or four faint furrows, some of which may be 
traced across the margin by close inspection. 
he depressed murginal band is rather wide, being about 
one-eighth of the greatest width of the pygidium; it is but 
little narrower at the extreme posterior portion. 
The elevation of the anterior portion of the axial lobe above 
the marginal edge of the pygidium, is nearly equal to the 
greatest width of that lobe; about 4™™ in present specimens. 
specimens, the c 
with the cephalic shield described, can only be inferred from 
glabella in the new species, while the pygidia vary in many 
features. 
Loeality—Calciferous, Ledge D, Rochdale. 
4 Bathyurus ? crotalifrons, n. sp. 
4 Figs. 4, 4a, 5 and 6, 
| Glabella low, convex, strongly conical, its sides being some- 
what concave a little anteriorly of the center. Its maximam 
_ width is very little less (about 34,) than its length exclusive of 
the occipital ring, and is found at about one-sixth of this length 
_ anteriorly to the occipital furrows. In the anterior third, the 
transverse diameter diminishes to two-thirds of the maximum 
and less. The front border and the posterior angles are well 
Shallow groove at the exterior margin over the eye. e an- 
the latter, exclusive of the occipital ring. The posterior 
limb of the cephalic shield extends out laterally at nearly 
right angles to the longitudinal axis. 
Movable cheeks low convex, tuberculated, with a rounded 
at margin ; ocular sinus moderate. General outline of 
> 
