122 NEW YORK. STATE MUSEUM 



indentation, remotely suggesting the rudimentary anterior glabellar 

 furrow of some species of Pliomerops or Heliomera. The basal 

 lobes are not so nearly square as is usual in Ceraurus, the posterior 

 glabellar furrows having an appreciable backward slant. Only a 

 fragment of a fixed cheek is preserved, not enough definitely to 

 locate the position of the eye, which organ would appear, from the 

 outlines of the free cheek, to have been well back and remote from 

 the glabella. In fact, this organ seems to have had about the same 

 position as in CerauruS dentatus. The cheeks are cov- 

 ered with large, rounded pits and small tubercles on the. inoscu- 

 lating rounded ridges between the pits. The eye line is prominent" 

 and covered with small tubercles. 



The hypostoma, known only from the specimen figured by me 

 in 1910, has an oval body portion covered with small tubercles and 

 a wide, smooth border which is incompletely preserved. 



The free cheek shows an elevated rounded rim which appears 

 to be smooth, the remainder of the surface being covered with 

 pits which are somewhat smaller than those on the fixed cheeks. 

 The eye is low and large, the lenses, which are small and circular 

 in outline, showing unusually well. No attempt was made to 

 estimate the number. 



No segment of the thorax is preserved but the cephalon and 

 pygidium are so characteristically Ceraurus-like that there can be 

 no doubt but that the thorax is of the ordinary type for the genus. 



The single pygidium is very large and especially wide at the front. 

 The conformation is as usual in Ceraurus, there being two greatly 

 developed, elongate spines at the sides, and three rings and a 

 posterior mound on the axial lobe. The unusual feature is the great 

 development of the pleural lobes of the second segment, which 

 form long spines which are prolonged a considerable distance 

 beyond the margin. These spines point almost directly backward, - 

 and do not bow outward as do the outer spines. Between these 

 spines of the second segment are two very short spines or denticles, 

 the spines of the third segment of the pygidium, but there is no 

 median spine. 



Measurements. The best cranidium is 38 mm long, the glabella 

 31 mm long, 30 mm wide at the front, and 25 mm wide at the back ; 

 the frontal lobe is 12 mm long. The smaller cranidium is 28 mm 

 long. The pygidium is about 45 mm long over all, 16 mm long as 

 measured along the axis. The width at the front is about 36 mm. 

 The great lateral spines appear to have been about 45 mm long, 

 and the second spines are 11 mm long. 



