NO. 2 CAMBRIAN AND LOWER OZARKIAN TRILOBITES 55 



CEDARIA new species 



PI. 10, fig. 6. (Nat. size.) Diagrammatic outline of the type species. 



Cedaria is characterized by the proparian-lilve course of the facial 

 suture The free cheeks commonly have long genal spines and are 

 often attached sufficiently strongly to remain a unit with the crani- 

 dium. 



Genotype- — C. proliftca new species. 



Range. — Upper Cambrian, Appalachians, Wisconsin. 



CHANCIA new genus 



PI. ID, fig. 4. (Nat. size.) Diagrammatic outline of the type species. 



Chancia differs from Elrathia in its wider fixed cheeks and wider 



rim, but more particularly in its small pygidium. It differs from 



Amecephalus in the frontal rim, wide fixed cheeks and occipital 



furrow. 



Genotype. — C. ebdome new species. 



Range. — Middle Cambrian, Rocky Mountains in Idaho. . 



CORBINIA new genus 



PI. 10, fig. 5. (Nat. size.) Outline drawing of the cranidium and associated 



pygidium. 



Corbinia resembles Eurekia in several characteristics but differs in 

 the absence of glabellar furrows, the structure of the frontal limb and 

 size and position of the eyes. 



Genotype. — C. horatio new species. 



Range. — Ozarkian. Mons formation. Alberta. 



CRUSOIA new genus 

 PI. 10, fig. 7. (X iH-) Diagrammatic outline of the type species. 

 Crusoia is characterized by the peculiar upturned front of the ce- 

 phalon, the small eyes situated far forward, and the minute pygidium. 

 Genotype. — C. cebes new species. 

 Range. — Middle Cambrian. Woolsey shale, Montana. 



DOKIMOCEPHALUS new genus 



PI. II, fig. I. (X H-) Restoration of the cephalon of the type species. 



Dokimocephalus is characterized by the long, pointed frontal limb, 

 the deep dorsal and glabellar furrows and the elaborate surface orna- 

 mentation. Thorax and pygidium as yet unknown, but possibly repre- 

 sented in the extensive unworked collections from the type localities. 



Genotype.- — Ptychoparia pernasiita Walcott (Mon. U. S. Geo!. 

 Surv., 8, 1884, p. 49, pi. 10, fig. 8). 



-Ra;/ (7^. —Upper Cambrian. Nevada and Missouri. 



