CAMBRIAN FOSSILS. 443 



Formation and locality : Middle Cambrian, Flathead formation ; north 

 side of Soda Butte Creek, below saddle on ridge between Pebble and Soda 

 Butte creeks, Yellowstone National Park. 



OBOLUS Eichwald. 



Subgenus LINGULEPIS Hall. 



Lingulepis Hall, 1863 : Sixteenth Aun. Eept. New York State Cab. Nat. Hist., p. 129. 



Lingulepis Meek and Hayden, 1864: Pal. Upper Missouri, Pt. I, p. 1. 



Lingulepis Hall, 1867: Trans. Albany Institute, Vol. V, p. 106. 



Lingulepis Hall and Clarke, 1892: Eleventh Ann. Eept. State Geologist New York 



(author's ed.), p. 231, PI. I, figs. 16, 17. 

 Lingulepis Hall and Clarke, 1892 : Pal. New York, Vol. VIII, Pt. I, pp. 59, 163. 

 Lingulepis Walcott, 1897 : Am. Jour. Sci., 4th series, Vol. Ill, p. 404. 

 Type, Lingula acuminata Conrad sp. = Lingula pinniformis Owen. 



A comparison of a series of specimens of Obolus (Lingulepis) acumi- 

 natus from the Potsdam terrane and the base of the Calciferous formation 

 of Saratoga, Washington, Franklin, and Jefferson counties, New York, and 

 from the same horizons in Ontario, Canada, with a large series of speci- 

 mens from the St. Croix sandstone of Wisconsin, leads to the conclusion that 

 Obolus (Lingulepis) pinniformis is a synonym of Obolus (Lingulepis') acumi- 

 natus. This makes Obolus (Lingulepis) acuminatus the tjqoe of the subgenus 

 Lingulepis, the original description of the genus being based upon speci- 

 mens from the St. Croix sandstone of Wisconsin. 



The further study of the types of the species that have been referred 

 to Lingulepis results in the elimination of all of them from the subgenus 

 with the exception of Obolus (Lingulepis) acuminatus and its variety meeki. 



The species that have been referred to Lingulepis heretofore are now 



referred as follows : 



Lingulepis dakotaensis M. aud H. = Obolus (Lingulepis) acuminatus. 

 Lingulepis pinniformis Owen = Obolus (Lingulepis) acuminatus. 

 Lingulepis minima Whitfield = Obolus (Lingulepis) acuminatus. 

 Lingulepis perattenuata Whitfield = Obolus (Liugulella) perattenuatus. 

 Liugulepis cuneolus Whitfield = Obolus (Lingulella) cuneolus. 

 Lingulepis ella H. and W.= Obolus (Lingulella) ella. 

 Lingulepis matiualis Hall= Obolus (Lingulella) matiualis. 

 Lingulepis msera H. and W. = Obolus (Lingulella) maera. 

 .Lingulepis ? minuta H. and W. = Obolella miuuta. 

 Lingulepis morsensis Wiuchell (Miller) = Lingula morsii. 

 Lingulepis prima M. and H. =Uicellomus politus. 



