Maryland Geological Survey 327 



annulation just within the genal angles, passing obliquely forward and 

 inward to the eye-lobe, thence forward and outward to the anterior margin. 



" Glabella extending three-fourths the length of the cephalon, sub- 

 pyriform, convex, bounded by a strong sulcus which becomes shallow over 

 the ocular lobes. Basal lobes pyriform ; baso-lateral furrows deep; antero- 

 lateral impressions faintly discei'nible. 



" Cheeks elevated about the orbital node and sloping abruptly to the 

 thickened margin. Palpebral lobes elevated ; visual surface not observed. 



" The Surface of the cephalon is ornamented by strong, scattered pus- 

 tules which become obsolete upon the border and the genal spines. Upon 

 the occipital ring is a single, strong, spiniform tubercle, generally accom- 

 panied by a smaller one on either side. The anterior and lateral margins 

 of the cephalon bear two rows of strong spines, one above the other ; those 

 of the upper row being the longer and having their bases upon the 

 proximal surface of the marginal rim. The proximal surface of this rim 

 lies vertically upon the margins of the cheeks, and hence the spines which 

 stand pei-pendicular to its surface, lie in the horizontal plane; as it ap- 

 proaches the frontal margin this rim becomes turned upward and slightly 

 reflexed, so that towards the anterior extremity the spines of the upper 

 row stand at an angle of nearly 45° to the horizontal. The spines of the 

 lower row are shorter, lying in the horizontal plane on the frontal margin, 

 and deflected below the horizontal plane on the genal margins. Of the 

 spines there are about 18 in the upper and 16 in the lower row. 



" A single fragment of a thorax associated with a cephalon of this 

 species shows a very wide and gently arched axis, 6 narrow and flattened 

 segments each bearing a number of strong pustules, of which there are 

 two longitudinal rows upon the pleurae, and for each segment of the axis 

 5 or 6 pustules which do not appear to be arranged in longitudinal rows. 

 This appearance may, however, be due to the imperfection of the specimen. 



Length of cephalon, 4 mm. ; width at the posterior margin, 7 mm. ; 

 length to the extremity of the genal spines, 8 mm." Hall, 1888. 



Occurrence. — Eomney Formation, Onondaga Member. One and 

 three-quarters south of Berkeley Springs, West Virginia. 



Collection. — U. S. National Museum. 



[E. M. Kindle.] 



