138 PALjEONTOLOGY OF NEW YORK. 



concave ; frontal margin elevated, rising to the height of the glabella, broad, 

 thickened and rounded. Palpebral lobes conspicuous. 



Glabella sub-pyriform, convex, slightly flattened above, bounded by a sul- 

 cus which is strong at the sides and obsolete in front. Baso-lateral lobes 

 strong; antero-lateral impressions well marked. 



Cheeks appressed and elevated along the lateral margins of the glabella. 



Thorax not observed. 



Pygidium semicircular ; length to width as 1 to 2. 



Axis prominent, elevated and longitudinally arched ; width less than one- 

 third that of the shield, rapidly tapering to an apex just within the posterior 

 border ; composed of nine annulations which are transverse, rounded and 

 separated by moderately broad sulci. 



Pleural evenly rounding to the flattened border, and bearing seven annula- 

 tions, which are strongly sulcate. Border broad, depressed or flat. All the 

 pleural annulations pass over the border to its edge, where the anterior and 

 posterior limbs are of equal strength. Doublure broad. 



Surface Ornamentation. The cephalon shows traces of low pustules over 

 the glabella, and upon the depressed frontal area, where they become elongate 

 or lachrymate, sometimes anastomosing, leaving elongate depressions between 

 them; the frontal border also bears an irregular row of conspicuous tubercles. 

 The pygidium is marked by regularly arranged pustules; a median row upon 

 the axis, bifurcating at the fifth or sixth annulation, thence backward con- 

 tinuing double until it becomes obsolete. Four rows of finer pustules are 

 also visible on the axis, two on either side of the median row. The pleurae 

 bear three or four rows of small pustules, and the interspaces of the crust 

 are minutely granulose, and punctate. The lower surface of the doublure is 

 marked by faint radiating or venate striations. 



Dimensions. The single fragment of the cephalon has a length of 7 mm. ; 

 the pygidium measures 6 nun. in length and 9 mm. in width. 



