Notes on ]{lclii>i()ii(l (111(1 R'Idlcd Fosxils 43 



in a given ^vi(llll varies greatly, from moderately fewer than 

 llio transverse striae in the same length to considerably more 

 nnmerous. 



Whitewater member of the Richmond group, at Richmond, 

 Indiana; found by John Misener. Occurring also at the same 

 horizon at the eastern edge of Dayton, Ohio, at the northern 

 end of Huffman hill, where the Springfield traction line crosses 

 (u-er the railroad to Wellston. 



Amphilichas sp. 

 Plate I, Fig. 2 



Specimen exposing the lower side of a pygidium and of 

 several of the posterior segments of the thorax. Margin of 

 pygidium with three pairs of lobes. The terminations of the 

 posterior pair are more or less rounded, and are separated 

 by a short narrow notch. The lateral pair of lobes is more 

 angular, and is separated from the posterior pair by a slightly 

 deeper and wider notch. The anterior pair is not preserved 

 in the specimen at hand, but probably resembled the middle 

 pair. A sharply defined rib extends, on the lower side of the 

 pygidimn, from the lateral margin of the axial lobe of the 

 pygidium approximately along the line separating the pos- 

 terior and middle pairs of lobes, and another extends between 

 the middle and anterior pairs. Beginning nearer the posterior 

 margin of the axial terminations of these lobes, an additional 

 rib extends diagonally forward toward the ends of the posterior 

 and middle pairs of lol)es. A corresponding median rib curves 

 .so as to approach the lateral posterior termination of the axial 

 lolie. The axial lobe of the pygidium is prominent anteriorly, 

 and becomes lower and narrower to a point about six-tenths 

 of the length of the pygidium from the anterior margin, after 

 which the sides of the axial lobe diverge again. All of the 

 ribs l)eneath the pleural lobes of the pygidium j)robal)ly locate 

 more or less distinct grooves on the upper, not exposed side 

 of the pygidinm. Two segments are indicated at the anterior 

 end of the axial lobe. The anterior one of the.se is short but 



