Notes on Cambrian Faunas. 251 
“The cephalic shie'd between the sutures is oblong-sub- 
quadrate. Glabella large, long ovato-cylindrical somewhat 
pointed in front, marked by three pairs of furrows, which 
are directed backward. Fixed cheek rather narrow, eyelobe 
distant from the glabella about two-thirds of the width of the 
latter, beginning opposite the third furrow; the cheeks are 
depressed in front of the eyes, and are united in front of 
the glabella; the united cheeks descend and are depressed 
toward the anterior margin, and there is a low marginal 
fold. 
“The facial suture is parallel in its general course to the 
longitudinal axis of the shield ; it cuts the margin obliquely, 
curving inward slightly between the margin and the eye- 
lobe * * * it then curves outward along the eyelobe and 
returns again and cuts the posterior margin as far from the 
glabella as the space from the ocular fillet to the front of 
the head-shield.” 
‘The thorax tapers regularly toward the base; only the 
first seven segments are known; the axis is wide and high, 
and the rings strongly arched; the pleure appear to be 
shorter than the ring, they are strongly arched, and bent 
downward at the extremity.” 
‘The pygidium is unknown.” 
Sculpture. The surface is smooth over most of the crust, 
but the area in front of the glabella is traversed by branch- 
ing and anastomosing raised lines. 
Size. The specimen originally described was a young, 
incomplete head. The following is given as the dimensions 
of the adult: Head shield between the sutures, length, 
il mm.; width, 12 mm. 
There are other features of the surface contour of this 
species worthy of notice; there are distinct furrows about 
the front and sides of the shield unusual in species of the 
genus Ellipsocephalus; beside the dorsal furrow, which is 
distinctly impressed around the front of the glabella, two 
furrows branch on each side from the anterior lateral angles 
of the glabella and extend, the one along the front of the 
ocular fillet and the other along the back. of it, the latter 
