317 



Found six feet below the lowest Trilobite bed, at Waii- 

 akah Cliff. 



Genus PH^THONIDES. Axgelin. 



[Ety. : PhaitJion, radiant.] 

 (1878: Pakeontologia Scandiuavica, p. 21.) 



Cephalon seiiii-cireular, with genal spines. Glabella 

 strongly arched, short and narrow, Avith strong and gener- 

 ally duplicate lateral furrows, and two small pyriform basal 

 lobes. Thorax of seven, or probably more, narrow segments, 

 with a wide axis. Pygidium proetoid, relatively large, bear- 

 ing from eight to twelve annulations upon the axis, and 

 eight or nine upon the pleurae. These annulations extend to 

 the margin, and are conspicuously duplicate their entire 

 length. Surface tubercled or smooth. 



Ph.^thonides gemm.^us. Hall and Clarke. (Fig. 262.) 

 (Pal. N. Y., Vol. VII., p. 186, PL XXIV.) 



Distinguishing CIiRracters. — Strong broad arched axis, 

 being nearly one-half the width of the body 

 on the anterior margin ; width increasing 

 backward for a short distance, and thence 

 tapering rapidly toward the pygidium, 



1 • i; ii J x; 1 -J- T 1 Fig. 262. Phcethon- 



bearmg from three to hve longitudinal uies gemmceus. pygid- 



„ . i 1 J T iuni enlarged two di- 



rOWS OI pustules; convex, SUlcate and ameteis:fromEiKhteen 



^ . . , . ,. Mile Creek (after Hall). 



pustulate pleurte ; semi-circular pygidium ; 

 axis with hve rows of tubercles, the middle one the strongest; 

 lateral lobes, with four, five, or six tubercles on each seg- 

 ment. 



Found in the "Hamilton grou}) * *, Eighteen Mile Creek, 

 Erie County." (Hall.) 



Genus CYPHASPIS. Buemeister. 



[Ety.: Cyphos, convex; aspis, shield.] 

 (1843: Burmeister: Organisation der Trilobiten, p. 103.) 



"Cephalon semi-circular; genal angles produced into long- 

 spines. Glabella strongly arched, short and narrow, with 



