386 The American Geologist. Tune, 1892 
lar except the tubercle. The pygidium is semi-elliptical, some- 
what wider than long, strongly elevated along the axis, trun- 
‘ated in front at the lateral thirds. The axis is cylindro-conical, 
width $ the pygidium, length }; it- bears an elongated tubercle 
on the axial line at the anterior $; short furrows indent the sides 
of the axis, opposite the ends of this tubercle. The side lobes 
are narrow and divided at the extremity of the axis by a furrow, 
connecting the dorsal and marginal furrows. 
~ Locality. St. John group, at Porter’s brook, St. Martin’s. 
AGNOSTUS ACADICUS Hartt, 1878. Plate 1x, fig. 7. Syn. Agnostus 
similis Hartt. 
Diagnosis.—Head convex, depressed. Limb narrow, slightly 
elevated. Glabella slightly less than 3 of the length of the head, 
long, elliptical, depressed convex, but more elevated than the 
other parts of the head; frontal lobe of the glabella, sub-cireular 
and occupying about 4 of the glabella; basal lobes small, but 
distinct. Cheeks of the same width throughout and united in 
front of the glabella; they are convex, more elevated along their 
inner margins, but sloping outwards roundly and evenly. The 
genial zone has a narrow, shallow, flat space or groove which fol- 
lows the limb; on going posteriorly along the lateral margins it 
loses gradually its width towards the posterior angles of the head. 
Thorax unknown. 
Pygidium similar to the head. The limb slightly raised, separ- 
ated from the sides by a shallow but well marked groove running 
parallel to the margin. This groove widens at the point where it 
bends to go forward along the sides, in such a way as to en- 
croach on the thin out of the limb; just before reaching the an- 
terior margin it narrows itself from the inner side, so as to cause 
the side lobes to widen somewhat anteriorly. These are narrow, 
flattened, about } as wide as the axis, narrowing to a point just 
behind the axis where they do not unite. The axis 
is about five-sixths of the length of the pygidium, lan- 
ceolated, flattened, more elevated than the side lobes of the pygi- 
dium. Dorsal furrows distinct. The axis has a small tubercle 
located on the median line about 4 its length from the front mar- 
gin. Surface smooth. 
Locality. St. John group, Saint John, N. B. 
The head of this species approaches that of A. neon, Hall & Whitfield. 
