NO. 3 CAMBRIAN AND OZARKIAN TRILOBITES 8/ 



gone much less fusion and the individual segments can readily be 

 distinguished. A more definite rim is also present. 



Dimensions. — Average length of large specimens, four cm. 



Genotype. — ConocorypJie (Conocephalites) kingii Meek. 



Stratigraphic Range. — Middle Cambrian, mainly. 



Geographic Distribution. — Cordilleran area and possibly elsewhere. 



Many species of the genus will be described and illustrated as the 

 study of the trilobites of this type progresses. One of them is the 

 Crepicephalus {€.) haguei Hall and Whitfield, from the Secret Can- 

 yon shale of the Eureka District, Nevada. The types come from the 

 White Pine District. (Geol. Expl. 40th Paral., Vol. 4, p. 210, pi. 2, 

 figs. 14, 15, 1877.) 



ELRATHIA KINGII (Meek) 



Plate 15, figs. 1-4 



Conocoryphc (Conocophalites) kingii Meek, 1870, Proc. Acad. Sci. Phila- 

 delphia, p. 63. (Description of species.) 



Conocoryphe (Pfychoparia) kingii Meek, 1873, 6th Ann. Rept. U. S. Geol 

 Surv. Terr., p. 487. Referred U. S. Geol. Expl. 40th Paral., 1877, Vol. 4, 

 p. 20, pi. r, fig. 4. White, 1877, Rept. U. S. Geogr. Surv., West looth 

 Merid., Vol. 4, p. 40, pi. 2, figs. 2a-c. (Described and illustrated.) 



Liostracus kingii Brogger, 1886, Geol. Foren. Stockholm Forhandl, bd. 8, 

 p. 205. (Generic reference changed.) 



Ptychoparia kingii Walcott, 1886, U. S. Geol. Surv. Bull. 30, p. 193, pi. 27 

 figs. 4, 4a. (Described and illustrated.) Research in China, 1913, Car- 

 negie Inst., Vol. 3, pi. 12, fig. 6. (Illustrated.) Beecher, 1895, Amer 

 Geol, Vol. 16, p. 171, pi. 8, figs. 5-7. (Noted and illustrated.) Grabau 

 and Shimer, 1910, N. A. Index Fossils, Vol. 2, p. 275, fig. 1573 

 (Illustrated.) 



Elrathia kingii Walcott, 1924, Smithsonian Misc. Coll., Vol. 75, No. 2, p. 56; 

 pi. II, fig. 4. 



Meek's very elaborate description gives the essential characters of 

 the species, even though he included more than one form. 



Formation and locality. — Middle Cambrian: (3W, lOy, loz, 30g) 

 Marjum formation, ic of section. In cliff two miles (3.2 km.) 

 southeast of Marjum Pass, House Range, Utah. 



(3y) Marjum formation. Shaly limestones forming id of section, 

 2.5 miles (4 km.) east of Antelope Springs, in ridge east of Wheeler 

 Amphitheater, House Range, Utah. 



(4) Wheeler formation. Drift below clififs near Antelope Springs, 

 House Range, Utah. 



(15b) Wheeler formation. Near Swazey Spring, House Range, 

 Utah. 



