292 CARBONIFEROUS FORMATIONS AND FAI'NAS OF OOI.ORAPO. 



that the delicate hut relatively strongci' oniainentation of Spiriferina solidirostrif 

 should have been lost. As the impressions agree with the shells referred to 

 Spirlfcr sp. 1> in other characters, I regard their specific identity, tliough not cer- 

 tain, as still rather probable. 



Locality and /(wjsrm.— Leadville district (stations 23Y2, 2373, 2375, 2377, 2378); 

 Leadville limestone. Castle Rock quadrangle (station 2367); Millsap limestone. Peb- 

 bles of Millsap limestone (?) in the Red Beds conglomerate, Larimer County (station 

 2364). 



Spirifer peculiaris Shumard? 



1855. Spirijerf pecuUaris. Shumard, Geol. Eept. Missouri, p. 202, pi. 0, figs. 7a, b. 

 Cheming group: Chouteau Springs, Cooper County, Mo. 



1874. Spirifer (Marlinia) peculiaris. White, U. S. Geog. Geol. Surv. W. 100th Mer., Prelim. Rept. 



Invert. Foss., p. 17. 

 Subcarboniferous: Mountain Spring, Old Mormon road, Nevada. 



1875. Spirifer {Martinia) peculiaris. White, U. S. Geog. Geol. Surv. W. 100th Mer., Repti, vol. 4, 



p. 90, pi. 5, figs. 7a, b. (Whole volume published in 1877. ) 

 Subcarboniferous: Mountain Spring, Old Mormon road, Nevada. 

 1895. Spirifera peculiaris. Keyes, Missouri Geol. Surv., vol. 5, p. 79. (Date of imprint 1894.) 



Kinderhook limestone: Chouteau Springs, Missouri. 

 1899. Reticularia {?) peculiaris. Girty, U. S. Geol. Surv., Mon., vol. 32, pt. 2, p. 557, pi. 70, figs. 8a, 8t. 



Madison limestone; Yellowstone National Park. 

 1901. Spirifer i^ceidiari.i? Weller, Acad. Sci. St. Louis, Trans., vol. 11, p. 165, pi. 14, figs. 6-9; p. 198, 

 pi. 20, fig. 1. 

 Kinderhook : Beds 4 and 7, Burlington, Iowa. 



This species was described by Shumard from the Chouteau limestone of Mis- 

 souri. Later it was identified by White at Mountain Spring, Old Mormon road, 

 Nevada. I recognized it in the Madison limestone of the Yellowstone National Park 

 region, and it also reappears in the fauna under discussion. Shumard evidently 

 regarded his reference of this form to Spirifer as doubtful, and White placed it in 

 the Martinia section of the genus. I referred it with a query to Reticularia, but in 

 typical material from the Chouteau limestone the presence of neither septa nor dental 

 lamellae is indicated in either valve, in which it difi'ers widely from our Lower 

 Carboniferous Reticidariae. It certainlj- difl'ers considerably from the dominant 

 Carboniferous types of Spirifer, and seems to be most closely allied to Sp. subcardi- 

 formis and Sp. suhorhicularis, which constitute what Hall and Clarke designate the 

 suhorbicularis type. 



While all probably belong to the subcardiformis section and are with little 

 doubt specifically identical with one another, that the forms from Nevada, Colorado, 

 and Yellowstone Park are correctly referred to Sp>. peGidiarin I now believe to be 

 doubtful. 



At all the localities in the West at which this form has been collected it seems 



