^0 NEW YORK STATE! MUSEUM 



ejes. The more aomplete speciinens show certain wrinkles or 

 ridges concentric to the margin, whose verj obscurity might be 

 regarded as veiling the eyes which from analogy one would ex- 

 pect to find in this creature; other shields show irregular 

 dwellings which are in part at least due to underlying carapaces 

 of Leperditia, but the most favorably preserved demon- 

 strate that it would be an error to let any such irregularities pass 

 as an apology for eyes. We cam find no e^ddience whatever that 

 the creature had either lateral compound eyes, central ocelli or 

 facial sutures, save that possible on the infolded surface. 

 There is furthermore no indication of any regular or persistent 

 subdivision of the head-shield, its form being evenly and smoothly 

 convex from the narrow and slightly flattened margin. The sur- 

 face is very finely and uniformly granulose or pustulose. 



A specimen obtained from the dolomite slabs of Litchfield 

 shows on the under impression a faint longitudinal, miedian 

 groove at the center of the carapace, with obscure traces of radi- 

 ally divergent grooves departing from the center toward the per- 

 iphery. We have already referred to this structure as suggesting 

 the often strong radial furrows on the head-shield of B u n o d e s 

 and have found therein an additional point of alliance between 

 these genera. That these represent the appendages of the cepha- 

 lothorax or are due to them seems to us, most probable. 



AMameti gently tapering with swelling marginal curve to the 

 telson. Strongly and subequally trilobed; axis slightly wider 

 than the pleurae; the dorsal furrows diverge to the third segment, 

 thence converge, becoming concave inwardly toward the posterior 

 extremity. The entire aspect of the abdomen is strikingly 

 tiilobitic. On the axis these segments are gently arched but in 

 themselves flat, tenuous and without ornaments; on the pleurae 

 their flatness is notable throughout their extent, their termina- 

 tions being flat points to which both upper and lower margins 

 quite regularly taper, the upper with a convex and the lower with 

 a concave curve. The extremities of these pleurae are thus free, 

 each projecting by itself. This feature becomes more pronounced 

 in passing posteriorly, and the pleurae of the last three segments 

 are not only very gradually tapering, but their retral curvature 



