Genus Agnostus.— Vogdes. 391 
author states that there is no fissure extending from the glabella 
to the anterior margin. The absence of this groove may be due to 
the state of preservation. This species agrees in every other re- 
spect with A. neon. Agnostus neon differs from A. communis in 
minute points, especially in the absence of the tubercle on the 
glabella. 
AGnostus oRION Billings, 1860 (ef. A. pisiformis Linné). 
Plate 1x, fig. 12. 
Diagnosis.—Length and breadth about equal, sub-circular, con- 
vex, a very narrow margin all around. Glabella not quite % the 
whole length, very convex; a transverse furrow at one-third the 
length from the apex; small triangular basal lobes without a median 
tubercle. Cheeks divided in front of the glabella by a furrow. 
Locality. Point Levis, Quebec. 
The same term was used by Barrande in 1846 for a species of this 
genus. If this species differs from A. pis/formisit is only in the absence 
of the median tubercle, which may be due to its state of preservation. 
There isa slight indication of the tubercle on one of my cabinet speci- 
mens from Point Levis. A pygidium from the same locality is similar 
to that of Agnostus pisiformis. 
AGNOSTUS JOSEPHA Hall, 1863. Plate 1x, fig. 17. 
Diagnosis.—Head semi-elliptical, margined by a fattened or 
concave narrow limb; geual angles produced into short spines. 
Glabella prominent, narrow, extending about $ the length of the 
head, and crossed by a shallow furrow near the anterior end. The 
posterior lobe is marked by an oblique furrow on each side; a 
small node onthe summit at the anterior termination. The trian- 
gular space on each side between the transverse and oblique fur- 
rows is like-wise elevated into alow node. The posterior central 
portion is gibbous. The bagal lobes small and triangular in form, 
Cheeks divided in front of the glabella by a furrow. Pygidium 
of the same form as the head. Axis prominent, subquadrate, 
wider than long, nearly 4 the length of the pygidium, bearing a 
node or short spine on its posterior extremity; sides and body of 
the pygidium, outside of the axis, highly convex. 
Locality. Trempealeau and elsewhere on the Mississippi about lake 
Pepin, Wisconsin. The species occurs with Anomocare wisconsensis and 
Ptychaspis granulosa. 
