52 
VICTORIA MEMORIAL MUSEUM. BULLETIN NO. I 
slightly towards the front, and extending almost to the anterior 
margin. Glabellar furrows nearly or quite obsolete. The facial 
suture begins at a point on the posterior margin back of the outer 
edge of the eye, runs diagonally inward while crossing the neck 
ring and furrow, encircles the eye, coming close to the glabella 
at the anterior comer of the palpebral lobe. From this point it 
turns outward again, but not far from the glabella, and reaches 
the anterior margin in front of the dorsal furrow, whence it ex- 
tends around the frontal margin. 
Eyes very large, from one-fourth to one-third the length of the 
glabella, and situated very close to the glabella and neck furrow. 
Free cheeks wide, with concave border, and spines of variable 
length at the genal angles. 
Thorax with nine segments; pleura grooved, ends blunt. 
Axial lobe of pygidium convex and prominent, with from one 
to three rings in the anterior end. Pleural lobes of pygidium 
with four pairs of ribs which usually extend across the concave 
border to the margin. 
Type: Bathyurus extans , Hall. 
Bathyurus extans, Hall. 
Asaphus extans , Hall, 1847. Palaeontology New York, Vol. I, 
p. 228, pi. 60, figs. 2a-2c. 1 
This species, which is, so far as is known, confined to the Low- 
ville, has a very convex pygidium whose outline tends to be 
triangular rather than rounded. The glabella is rather smooth, 
but has a few fine pustules on the top. The pygidium is about 
three-fourths as long as wide. 
Bathyurus perplexus, Billings. 
Bathyurus perplexus, Billings, 1865. Palaeozoic Fossils of 
Canada, Vol. I, p. 364, fig. 350. 
This species, as has already been pointed out by Walcott 3 , is 
probably a synonym of B. extans . The specimen is a pygidium 
from Bonne bay, Newfoundland. 
Hn the present paper, only the reference to the original publication of each 
species will be given. The full bibliography and synonomy will be given in 
the final parser. 
2 Bull. 30, U.S. Geol. Survey, 1896, p. 20. 
