754 MR. p. E. C. KEED ON THE LOWER PALEOZOIC [NoV. 1 899, 



Head-shield broadly semicircular in shape, strongly convex from 

 side to side and also from back to front. 



Glabella regularly convex, swollen, subcylindrical, slightly broader 

 in front than at the base, but not inflated in front or overhanging 

 the margin as in E. sexcostatus. Anterior end of glabella obtusely 

 rounded, jN'eck-furrow at the base strong, slightly arched forward. 

 Three pairs of short lateral furrows indent the sides of the glabella ; 

 the basal furrows are the longest, and are slightly directed forward, 

 marking off a pair of very narrow basal lobes not wider than the 

 neck-ring. The second pair of furrows is usually short, but some- 

 times continued weakly over the surface of the glabella, curving gently 

 backward so as nearly to meet the basal furrows, and thus faintly 

 defining a pair of middle lateral lobes separated from each other by 

 a space equal to about a quarter the width of the glabella. The 

 anterior pair of furrows is very short, merely indenting the sides of 

 the glabella, and they are situated at the same distance from the 

 second pair as the latter are from the basal pair. 



The frontal lobe is about double the length of the anterior pair 

 of lobes, and does not overhang them laterally. It is rounded in 

 front, where it is encircled by a marginal furrow which runs into 

 the deep and strong axial furrows. A narrow tuberculate, almost 

 horizontal border is thus marked off sharply from the anterior end 

 of the glabella, as in E. Seebachi, Schmidt, and a few other species. 

 Where the marginal furrow meets the axial furrow a small deep 

 pit is found on each side. 



The fixed cheeks are convex and much swollen, being elevated 

 nearly as much as the glabella. They are produced backward, and 

 strongly bent down towards the genal angles. 



The eye-lobe is large and elevated, standing up prominently from 

 the cheek. 



The facial suture curves backward and outward from the front 

 of the glabella to about the level of the second lateral furroWy 

 where the eye is situated at a distance from the axial furrow equal 

 to about the width of the glabella. From this point the facial 

 suture bends sharply outward, and running nearly parallel to the 

 posterior margin of the head-shield, cuts the outer edge immediately 

 in front of the genal angle. 



The free cheek is triangular, with a rounded border marked off 

 by a strong marginal furrow from the convex tuberculated inner 

 portion, which rises steeply up to the tall conical eye borne on a 

 short constricted stalk. 



The neck-lobe and segment are narrow and rounded, the latter 

 widening a little towards the genal angles. 



The whole surface of the head-shield is ornamented with small 

 tubercles, but on the fixed cheeks there are in addition a few of 

 larger size ; and three or four of such larger tubercles are noticeable 

 on the free cheeks. 



The thorax is known only from two young individuals which are 

 almost complete. These show twelve body-rings, with an axis mea- 

 suring about one quarter the whole width of the thorax. The axis 



