l88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 64 



Surface more or less roughened by small, shallow and deep pits, 

 some of which result from weathering of the surface. 



A cranidium 17 mm. in length has a width of about 14 mm. at 

 the palpebral lobes. 



The cranidium is similar to that of A. pomona (pi. 25, fig. 6) in 

 having narrow fixed cheeks .and palpebral lobes back of the center 

 of the cranidium. It differs from A. subcoronatum in its narrow 

 fixed cheeks, large size, and elevated palpebral lobes, Stratigraph- 

 ically it occurs about 1,200 feet above Alokistocare subcoronatum in 

 the Blacksmith Fork section.^ 



Formation and locality. — Middle Cambrian: (55s) Bloomington 

 formation ; 2b of section ; ^ about 9 miles ( 14.4 km.) above the mouth 

 of Blacksmith Fork Canyon, and 15 miles (24 km.) east of Hyrum, 

 Cache County, Utah, 



Genus LONCHOCEPHALUS Owen 



Lonchocephalus Owen, 1852, Rept. Geol. Wis., Iowa, Minn., p. 575. (De- 

 scription.) 



Lonchocephalus Hall, 1863, Sixteenth Ann. Rept. New York State Cab. 

 Nat. Hist., pp. 147, 160. (Quotes Owen's description and groups species 

 belonging to several genera under Lonchocephalus, p. 160.) 



Lonchocephalus Shumard, 1863, Trans. Acad. Sci. St. Louis, Vol. 2, p, 104, 

 (Considers Lonchocephalus chippewaensis the type of the genus, but 

 considers the genus synonymous with Conoceplialites.) 



Lonchocephalus Hall, 1867, Trans. Albany Inst., Vol. 5, p. 129. (Reprint 

 of remarks of 1863.) 



Lonchocephalus Owen, Miller, 1889, North Amer. Geol, and Pal., p. 555, 



Original description by Owen. " In this small and singular genus 

 the highly arched glabella is either undivided, or has only two very 

 obscure furrows, A spine of greater or less length projects back- 

 wards from the base of the glabella, in the median line of the body 

 over the thoracic segments (fig, 12, pi, lA), The pygidium found 

 associated in the same beds is semilunar, with little or no border, 

 and has four segments on the axial lobe," 



Following the above description is the description of Loncho- 

 cephalus chippewaensis. The generic description points clearly to 

 this species, but the figure referred to is that of L. hamulus. The 

 author also illustrates three cranidia of L. chippewaensis (pi. i, figs. 

 6, 14; pi, I A, fig. 9), which come within the generic description 

 much more nearly than the cranidium of L. hamulus. The species 

 most nearly related to L, hamulus is that illustrated and named by 

 Owen Crepicephalus ? wisconsensis (pi, i, fig, 13), 



Smithsonian Misc. Coll., Vol. 53, 1908, pp. 194-196. 

 Idem, p, 194, 



