188 PALEOZOIC PALEONTOLOGY. 
PTEROPODA. 
CONULARIA TRENTONENSIS Hall. 
Plate XIII., Figs. 7-8. 
1847. Conularia trentonensis Hall, Pal. N. Y., vol. L., p. 222, pl. 
58, figs. 1 a-f. 
Description—Shell of medium size, pyramidal in form, quadrangu- 
lar in cross-section, the sides diverging from the apex at an angle 
of about 25°. The sides slightly convex, the angles furrowed. Each 
side marked by a series of angular, transverse costw, which are directed 
obliquely forward toward the aperture from each lateral margin, form- 
ing a rounded angle of about 130° at the median line; from two to 
four of these coste occupy the space of 1 mm., being closer together 
and finer near the apex of the shell and becoming progressively coarser 
towards the aperture. The furrows between the coste are wider than 
the ridges, rounded in the bottom, and are crossed at right angles by 
fine, raised bars joining adjacent cost, which are somewhat closer 
together than the cost themselves and not quite as high. 
The dimensions of a specimen which is somewhat incomplete at 
the apex are: length, 38 mm.; diameter at aperture, 18 mm. 
Remarks.—This is the only species of Conularia which has been 
recognized in the Trenton limestone of New Jersey. It is the common 
Trenton species of the genus which occurs in New York and other 
localities. 
CEPHALOPODA. 
ORTHOCERAS TENUISTRIATUM (Hall). 
Plate XIII., Figs. 1—2. 
189%. Orthoceras tenuistriatum Clarke, Pal. Minn., pt. II., p. 788, 
pl. 55, figs. 4 and 6. 
Description.—“Shell long, straight, gradually expanding. Sutures 
direct; septum regularly concave and very slightly oblique. Sipho 
