LOWER CARBONIFEROUS FOSSILS. 557 



Compared with the Burlington form, R. cooperensis var. is smaller, less 

 transverse; fold and sinus less pronounced; area proportionally not so 

 broad. 



The specimen figured is from the Eureka district, Nevada. The 

 original shape and proportions are better maintained. 



Formation and locality: Madison limestone, Crowfoot Ridge, Gallatin 

 Range, top of bed 25; J. P. Iddings and Gr. M. Wright. Lower Carbon- 

 iferous, Eureka district, Nevada; Dry Canyon, Utah. 



Reticularia (!) peculiaris Shumard. 

 PI. LXX, figs. 8a, S&. 



Spirifer f peculiaris Shiunard, 1855: Geo!. Rept. Missouri, p. 202, PI. C, figs, la, lb. 

 Spirifera [Martinia) peculiaris White, 1875 : Wheeler's Expl. Surv. W. 100th Merid., 

 Yol. IV, p. 90, PI. V, figs, la, lb. 



This species is so rare in the Yellowstone National Park, and its 

 preservation is so unsatisfactory, that any less striking form could scarcely 

 be identified. 



It can be distinguished from R. suhrotundata by its larger and less 

 numerous plications, of which there are only six or seven on either wing, 

 while the fold and sinus are simple. 



R. peculiaris is found in the yellow sandstone at Burlington, Iowa, and 

 in the brown limestone of Chouteau age at various places in Missouri. 



I am not confident that this is correctly referred to Reticularia. Exfo- 

 liated specimens from the Chouteau limestone appear to have possessed a 

 finely lamellose-spinose surface. 



Formation and locality: Madison limestone, summit of Three River 

 Peak, Grallatin Range; J. P. Iddings. East side of Lamar Valley, mouth 

 of Soda Butte Creek, Absaroka Range; W. H. Weed. Kinderhook age, 

 Cooper County, Missouri; Mountain Spring, Nevada. 



Reticularia (?) subrotundata Hall. 

 PI. LXX, figs, la, lb. 



Spirifera subrotimdata Hall, 1858 : Geol. Surv. Iowa, Vol. I, Pt. II, p. 521, PI. VII, fig. S. 

 Keyes, 1895 : Geol. Surv. Missouri, Vol. V, p. 7S. 



I have this species from a single locality beyond the confines of the 

 Yellowstone National Park, but associated with a fauna clearly identical 

 with that of the Madison limestone. 



