CAMBRIAN FOSSILS. 461 



limestone, with a few fragments of the pygidium. The material is too poor 

 to properly illustrate the species, and a figure is introduced that was drawn 

 from specimens collected in the Middle Cambrian shaly beds of the Coosa 

 Valley, Alabama. A detailed description of the species and full illustrations 

 will be given in a memoir on the Middle and Upper Cambrian faunas, now 

 being prepared. 



The type specimens of the species were described by Dr. Shumard 

 from Llano County, Texas. I collected a series of specimens from the type 

 locality, and a comparison of these with those from Moss Agate Springs, 

 near Camp Baker, Montana (described as Arionellus tripunctatus by Whit- 

 field), and the Coosa Valley, Alabama, shows them to belong to one species. 



Formation and locality : Middle Cambrian, Flathead terrane, north 

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

 and Soda Butte Creek ; Flathead terrane, Crowfoot section, Gallatin Range, 

 Yellowstone National Park. 



Ptychoparia (Lonchocephalus) hamulus Owen! 



Lonchocephalus hamulus Owen, 1852: Geol. Kept. Wisconsin, Iowa, and Minnesota, 



p. 576, PI. IA, figs. 8, 12. 

 Conocephalites hamulus Hall, 1863: Sixteenth Ann. Eept. New York State Mus. Nat. 



Hist, p. 166, PI. VII, figs. 43, 41; PI. VIII, figs. 25, 26. 



One imperfect head is all there is in the collection on which to base 

 the presence of this species. Little more can be said than that there is a 

 form which represents it. 



Formation and locality : Middle Cambrian, Flathead formation, north 

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

 Butte Creek, Yellowstone National Park. 



Ptychoparia (Lonchocephalus) wisconsensis Owen sp. 

 PI. LXIV, figs. 1, la-c. 



Crepicephalus (?) wisconsensis Owen, 1852: Eept. Geol. Snrv. Wisconsin, Iowa, and 



Minnesota, description, PI. I, fig. 13. 

 Dieellocephalus latifrons Shumard, 1863: Trans. St. Louis Acad., Vol. II, p. 101. 

 Conocephalites loisconsensis Hall, 1863: Sixteenth Ann. Kept. New York State Oab. 



Nat. Hist., p. 164, PI. VII, figs. 39-41; PI. VIII, figs. 22-24, 27, 28. 



This species occurs in abundance in thin-bedded limestone in the 

 northeastern portion of the Park. It is associated with Ptychoparia (?) clia- 



