6o SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



Genotype. — Dicellocephalus iole Walcott (Men. U. S. Geol. Surv., 

 8, 1884, p. 43, pl- 10, fig. 19). 



Range. — Upper Cambrian. Eureka District, Nevada. 



UCEBIA n^w genus 



PI. 14, fig. 4. (X3. Outline drawing of type species. 

 Ucebia is closely allied to Kingstonia, but differs by having a shallow 

 dorsal furrow. 



Genotype. — U. ara new species. 



Range. — Upper Cambrian. Appalachians, Rocky Mountains. 



UTIA new genus 



PI. 13, fig. 3. (X 2.) Restoration of type cranidium. 



Utia is a very curious trilobite in which the frontal limb stands 

 vertically, with wide fixed cheeks, furrowed by peculiar longitudinal 

 depressions. Specimens with a portion of thorax in the collections. 



Genotype. — U . curio new species. 



Range. — Middle Cambrian. Spence shale, Idaho. 



WILBERNIA new genus 



PI. 13, fig. 4. (Nat. size.) Outline drawings of dorsal and side views of the 



type cranidium. 



Wilhernia includes among its numerous species the well-known 

 Ptychoparia diademata (Hall). 



Genotype.— P. pero Walcott (Proc. U. S. Nat. Mus., 13, 1890. 

 p. 274, pi. 21, fig. 6). 



Range. — Upper Cambrian. Mississippi Valley and Rocky Moun- 

 tains. 



XENOSTEGIUM new genus 



Pi. 13, fig. 5. (Nat. size.) Outline drawing of the type species. 



Xenostegium contains many species, some of which were formerly 

 referred to Megalapis. It is characterized by the spined pygidium. 



Genotype. — Asaphus {Megalapis f) goniocercus, Meek (6th Ann. 

 Rept., U. S. Geol. Surv. Territories, 1873, p. 480). 



Range.— Upper Ozarkian and possibly Canadian, Cordilleran 

 region. 



PLATYPELTIS Calloway. PSILOCEPHALUS Salter 



PI. 14, figs. 5 and 8. Outline drawings of the genotypes. Platypeltis croftii 

 and Psilocephahis innotatus were introduced for comparison with Symphysti- 

 rina. (Smith. Misc. Coll., vol. 75, no. i, 1924, P- 38.) 



