NO. 7 PTYCHOPARIID TRILOBITES — RASETTI 35 



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 nidium, X 12 (boulder G-24) ; U.S.N.M. No. 123883, plesiotype. 



7, Free cheek, X 6 (boulder G-24) ; U.S.N.M. No. 123883, plesiotype. 



8, Largest, exfoliated cranidium, X 2 (boulder O-37) ; U.S.N.M. 

 No. 123884, plesiotype. 



Figs. 9-14. Periomma walcotti Resser 24 



9, 10, 14, Lateral, frontal, and dorsal views of cranidium, X 4 (boulder 

 O-24) ; U.S.N.M. No. 123879, plesiotype. 11, Partly exfoliated cra- 

 nidium, X4; U.S.N.M. No. 23529, holotype. 12, Partly exfoliated 

 cranidium, X 4 (Island of Orleans) ; U.S.N.M. No. 23529, plesiotype. 

 13, Cranidium, X4; U.S.N.M. No. 123879, plesiotype. 



Plate 6 



Figs. 1-6. Riinouskia typica Resser 31 



1-3, Dorsal, lateral, and frontal views of cranidium, X4; U.S.N.M. 

 No. 64998, holotype. 4, 5, Lateral and dorsal views of smaller cra- 

 nidium, X4; U.S.N.M. No. 64998, plesiotype. 6, Small cranidium, 

 X6 (boulder at Bic) ; U.S.N.M. No. 94748, holotype of Rimouskia 

 spinosa. 



Figs. 7, 8. Luxella crassimarginata Rasetti, new genus, new species 22 



Dorsal and lateral views of cranidium, X 4 (boulder B-6) ; U.S.N.M. 

 No. 123885, holotype. 



Figs. 9-1 1. Luxella lux (Walcott) 21 



Dorsal, lateral, and frontal views of cranidium, X4 (Peyto limestone; 

 west ridge of Mount Schaffer, Yoho National Park, British Co- 

 lumbia) ; U.S.N.M. No. 123876, plesiotype. 



Figs. 12-15. Antagmusf longifrons Rasetti, new species 12 



12, Cranidium, X4 (boulder M-9) ; U.S.N.M. No. 123861, paratype. 

 13, 14. 15. Dorsal, lateral, and frontal views of cranidium, X4 

 (boulder M-9) ; U.S.N.M. No. 123860, holotype. 



Figs. 16-18. Antagminae, genus and species undetermined 27 



Frontal, lateral, and dorsal views of cranidium, X 4 (boulder M-9) ; 

 U.S.N.M. No. 123877. 



