NO. 3 CAMBRIAN TRILOBITES 199 



Ptychoparia (Lonchoccphalus) wisconsensis (Owen) Walcott, 1899, 

 Monogr. U. S. Geol. Surv., Vol. 32, Pt. 2, p. 461, pi. 64, figs, i, la-b. 

 (Notes occurrence in Wyoming, and illustrates. By error a pygidium 

 of Ptychoparia ? diadcviata Hall is referred to this species, pi. 64, fig. 

 ic, and a cranidium of Saratogia hamulus (Owen), fig. lb.) 



Ptychoparia (Lonchocephalus) wisconsensis (Owen) Walcott, Grabau and 

 Shimer, 1910, North American Index Fossils, Vol. 2, p. 277. (Notes 

 occurrence of species.) 



This species is known only by the cranidium, free cheeks, and 

 possibly pygidium. In the Franconia formation of Wisconsin and 

 Minnesota it occurs in the form of casts in fine-grained sandstone, 

 and its outer surface is not preserved, and the same is true of the 

 specimens from the Yellowstone National Park, which are slightly 

 eroded as they occur on the limestone slabs. Saratogia wisconsensis 

 dififers from 5". calcifera in many details of the cranidium, notably in 

 the frontal limb and rim. It is quite unlike ^. hamulus (Hall). 



Formation and locality. — Upper Cambrian: (i5ie) Gallatin lime- 

 stone; north side of Soda Butte Creek, below saddle on ridge 

 between Pebble Creek and Soda Butte Creek, Crowfoot section, 

 northeastern corner of Yellowstone National Park, Wyoming. 



Also (79) Eau Claire formation; Hudson, St. Croix County; 

 (99a) Franconia formation; near Pilot Knob, Adams County; 

 (83*) Trempealeau, Trempealeau County ; all in Wisconsin. 



Also Franconia formation; (97) Reeds Landing, foot of Lake 

 Pepin, Wabasha County ; and (339g) near Winona, Winona County ; 

 both in Minnesota. 



And (86c) Eau Claire formation; Lansing, Allamakee County, 

 Iowa. Southeast of city at low-water mark. 



This species occurs at other localities in Wisconsin and Minnesota, 

 but at present I do not have specimens before me for identification 

 except from those given above. 



Family CERATOPYGiDyE 

 Genus CREPICEPHALUS Owen 



Crepicephalus Owen, 1852, Rept. Geol. Surv. Wis., Iowa, Minn., p. 576, pi. 



I, fig. 8, tab. Ai, figs. 10, 16, 18. (Describes genus and refers to 



figures of cranidium and pygidium of the species C. iowetisis.) 

 Crepicephalus Hall, 1863, Sixteenth Ann. Rept N. Y. State Cab. Nat. 



Hist., p. 147. (Reprints Owen's description, and comments on genus. 



Refers species C. iowensis to Conocephalites.) 

 Crepicephalus Shumard, 1863, Trans. Acad. Sci. St. Louis, Vol. 2, p. 103. 



(Considers Crepicephalus as identical with Conocephalites.) 

 Crepicephalus Hall, 1867, Trans. Albany Inst., Vol. 5, p. 130. (Reprint 



of paper of 1863.) 



