L02 PALAEONTOLOGY OF NEW YORK. 



the steep frontal slope, curving and approaching each other at the edge of 

 the frontal border and uniting upon the doublure. 



Glabella sub-pyriform, very convex, longitudinally arched, rising abruptly 

 on all sides from the lateral furrows, which are not deeply impressed; gibbous 

 on the anterior slope, slightly flattened at the summit. Length equal to 

 four-fifths the length of the cephalon; width at the base more than one-third 

 that of the cephalon. Four pairs of lateral furrows and one pair of acces- 

 sory furrows are discernible upon the cast of the lower surface, but upon 

 the crust only the stronger of them can be seen as faint lines interrupting 

 the ornamentation. The first pair is situated at about one-third the length 

 of the glabella from the anterior margin, and appear as faint elongate pits 

 not distant from the marginal furrow. The other three pairs are longer 

 and inclined backward, none except the fourth pair extending to the mar- 

 ginal furrow. The accessory furrows take their origin just in front of the 

 proximal ends of the fourth furrows, and are strongly inclined backward. 

 The occipital lobes are moderately strong in the cast but are inconspicuous 

 where the crust is retained. Occipital furrow narrow, the anterior side 

 nearly vertical and the posterior side almost horizontal, widening on the 

 cheeks and continuous with the marginal sulcus. Occipital ring broad, flat, 

 narrowing to the axial furrows and widening again to the genal angles, bear- 

 ing a small pointed tubercle upon the axial line. 



Cheeks grooved and depressed about the orbital lobe, thence abruptly de- 

 llected to the broad margin. 



Eyes approximate, prominent, elevated to almost the height of the glabella ; 

 orbital ridge conspicuous ; palpebral lobe small; palpebral furrow elevated 

 and moderately deep. 



Thorax sub-rectangular, margins nearly parallel. Length to width as 1 to 1.3. 

 Axis arched. 



Pleura flattened above for one-half their width, and thence somewhat 

 ibruptly deflected. The segments are transverse, somewhat flattened, 

 grooved upon the pleurae and beveled for one-half their length 



