1896. | NEW YORK ACADEMY OF SCIENCES. 229 
cludes Hicks’ species from A. gibbus, but not from A. punctuosus 
which is thus ornamented; the latter species, however, has con- 
fluent side-lobes to the caudal shield, while in A. scutalis these 
lobes are divided by a furrow. A. Nathorsti is another species that 
is tuberculate on the sides, and is also nearer the size of A. scuta- 
lis, but this species has the sides of the posterior lobe of the 
glabella furrowed, and has marginal spines to the pygidium, 
characters which are absent from A. scutalis; so we find our- 
selves unable to recognize Hicks’ species in the P. Davidis sub- 
fauna of America.* 
A«nostus Natuorst1, Broegger. 
Agnostus Nathorsti, Broegg. Om Paradoxides skifrene red 
Krekling, p. 68, pl. v., fig. 1. 
Agnostus exsculptus, Ang. part (7. e., “ pygidium”) Palzon- 
tologia Scandinavica, p. 7, pl. vi., fig. 8 (Fide Tullberg). 
Agnostus Nathorsti, Tullberg. Agnostus Arterna vid. Andra- 
rim, p. 21, ploig tio. 9. 
“ Head rounded, enclosed by a subfiliform narrow marginal 
fold. Glabella bilobate, anterior lobe narrower than the pos- 
terior, oblong, equally rounded-acuminate. Posterior lobe almost 
equal in length to one-half of the head, impressed by two deep 
grooves on each side, rounded behind, pressed together and 
high, furnished with a raised point ; basal lobes separated from 
the glabella by a posterior furrow, rounded, connected behind 
the glabella. Cheeks separated in front of the glabella, sculp- 
tured with longer or shorter lateral furrows.” 
“The rachis of the thorax has elliptical lateral tubercles. 
Pygidium. rounded behind, furnished with a somewhat broader 
bidenticulate marginal fold. Rachis with three joints, pointed 
behind, front joint shorter than the others, slightly wider, di- 
vided into three parts by two longitudinal depressions ; the mid- 
dle joint keeled, produced backward into a point. Posterior 
joint rather long, squeezed in the middle part by an arched de- 
pression, ornamented with a small elevated point in the depres- 
sion. Lateral lobes minutely granulated, narrowed behind, 
separated behind the rachis.” 
Size.— Length and width of the shields, 44 mm.” 
Horizon and Locality.—Dark shales of Div. 1d!. Porter’s 
Brook, St. Martin’s N. B., Canada, scarce. 
Tullberg remarks in his work cited above, that the shield fig- 
ured by Angelinas the pygidium of Agnostus exsculptus is really 
the head shield of this species (A. Nathorstt). 
*Figures 13, 14, pl. v., referred to A. scutalis are not of this species, but represent some 
species of the Limbati section (a Fallax). 
