OF DENISON UNIVERSITY. 
107 
This corresponds to a much more evident (although narrow) ridge, on 
the pygidium associated with these glabellae. In the occipital furrow 
at about two-thirds the distance of its postero-lateral margin from the 
granule is a deep, very distinct pit becoming shallow in older 
specimens. 
From this the dorsal furrow extends inwards as a deep groove 
forming a broad, oval depression opposite the palpebral lobe, thence it 
extends as a shallow groove, rapidly becoming indistinct, in an out- 
ward direction, terminating in a small pit, which can be easily recog- 
nized even in specimens which do not show the connecting part of the 
groove distinctly, as is usually the case. This pit contains a minute 
granule. It is situated at two-thirds the distance of the anterior 
margin from the palpebral lobe. Half way between this pit and the 
anterior margin is a minute granule, easily visible on wetting the speci- 
men. Widest part of the glabella lies between the palpebral lobes, 
anterior to which it becomes narrower and again widens reaching 
almost the same width at a point just behind the junction of the facial 
suture with the anterior margin. Facial suture extending from the 
edge with a distinct outward curvature to a point opposite the terminal 
pit of the dorsal furrow where it makes a rapid curve inwards to its 
junction with the anterior margin, in which the facial suture seems to 
terminate without any break. Palpebral lobe rounded. Facial suture 
behind the palpebral lobe starts from the posterior incurved extremity 
of each eye, and curves rapidly outward, cutting the margin directly 
behind or a slight distance beyond a vertical line drawn from the most 
prominent part of the palpebral lobe to the occipital line. Greatest 
elevation of the glabella lies between the palpebral lobes. 
Pygidium semi-circular in outline, becoming slightly paraboloid in 
larger specimens, with a narrow more or less strongly marked ridge. 
Ridge extending from the posterior margin upwards, usually not 
reaching the middle of the pygidium. It can always be recognized. 
Along the anterior margin lies a groove, which is somewhat straight 
along its middle third, a small inward curvature near the middle, being 
very slight, aids in this appearance. At either side the groove makes 
a short curve inwards, and then outwards, approaching the lateral 
margin, along which it extends for a short distance, rapidly becoming 
obsolete. The deflection of the antero-lateral border causes a raised, 
ridge-like eminence to remain between it and the antero-lateral portion 
of the marginal groove. Pygidium flattish along the upper anterior 
