85 



abdomine in spinam arcuatam acutam utrinque ex- 

 tenso. 



The exact contour of this species cannot be per- 

 fectly ascertained from our specimen; it seems, how- 

 ever, to have been lunate. The horns of the crescent 

 which form the posterior angles, are very distinct, 

 and they project like curved spines, some distance on 

 each side of the head. The middle lobe or front is 

 faintly scalloped on each side along the cheeks. The 

 cheeks are rather large, and are furnished with two 

 small oculiform tubercles, very remote from each other, 

 and quite near to the anterior portion of the buckler. 

 The abdomen is composed of twelve articulations. 

 The lateral lobes of the abdomen are flat, and each of 

 the ribs, at about half their extent, is marked on the 

 upper surface, with an elevated pimple. These little 

 pustules are nearly on a line with the oculiferous tu- 

 bercles of the buckler, and present two parallel ranges 

 down the body, one on each side of the middle lobe, 

 and are terminated by a curved spine, which projects 

 to some distance beyond the tail of the animal. 

 Length one inch and a fourth. 



This remarkable organic relic was found near 

 Newport, in the State of New York. It is embedded 

 in black limestone shale, and so exceedingly depress- 

 ed is this animal, that a very thin lamen of the slate 

 removed from the surface would destroy every ves- 

 tige of its appearance. I am indebted to my early 

 friend, Professor T. R. Beck, for the use of this valu- 

 able petrifaction, which now belongs to the cabinet 

 of the Albany Institute. 



