17 



erons strata, and to which period I have referred the rocks from which 

 the specimens were collected. The first line gives the localities of the 

 specimens contained in the collections, and the second those Subcarbon- 

 iferous localities which furnished the types of all the species named ex- 

 cept one. 



Syrinfjopora Sarveyi White ? 



EwelTs Spring, Arizona. 



Burlington limestone, Burlington, Iowa. 

 Productiis Farrus Meek and Worthen. 



Mountain Spring, Old Mormon road, Nevada. 



Chester limestone, Chester, Illinois. 

 Strophomena rJiomhoidalis* Wilckins. 



Mountain Spring, Old IMormon road, Nevada. 



Kinderhook formation of Illinois and Iowa and elsewhere. 

 Spirif/era obmaxima McCbesney. 



Monntain Spring, Old Mormon road, Nevada, and below Opliir 

 City, Utah. 



Keokuk limestone of Iowa and Illinois. 

 Sjiiri/er [Martinia) peeuUaris Shu.nard. 



Mountain Spring, Old Mormon road, Nevada. 



Kinderhook, formation of Missouri and Iowa. 

 Spirifer centronata Winchell. 



Mountain Spring, Old Morman road, Nevada. 



Waverly sandstone, Cuyahoga Falkj, Ohio. 

 Spirifer striatus Martin. 



Mountain Spring, Old Mormon road, Nevada. 



Burlington limestone (/S'. Grimesi), Burlington, Iowa. 

 Spirifer {Syringothyris) extenuatus Hall. 



Mountain Spring, Old Mormon road, Nevada. 



Kinderhook formation of Iowa and Missouri. 

 Terehratula BurUngtonensis White. 



Mountain Spring, Old Mormon road, Nevada. 



Kinderhook formation, Burlington, Iowa. 

 Pro'hictus Prattenianus Norwood ( = ? P. kevicostus White). 



Below Ophir City, Utah. 



Kinderhook formation, Burlington Iowa (P. la'vicosfus). 

 Orthis Miehilini var. Burlingtonennis Hall ' 



Below Ophir City, Utah. 



Burlington limestone, Burlington, Iowa. 



CARBONIFEROUSf PERIOD. 



ECHINODERMATA. 

 Genus Arch^ocedaris McCoy. 



Arch^eocidaris trudifer («p. nor.) — Interambulacral plates com- 

 paratiV'Cly broad, rather thin, with a row of small tubercles forming an 

 elevated border all around ; areolar surface apparently plain ; central 

 tubercle small, perforated in the center, surrounded at its base by a 



^Almost world-wide in its distribution, but is believed not to exist in strata of later date 

 than the Subcarbonit'erons. 



tl use this term to indicate all the strata between the Subcarboniferons below and the 

 Permian above, and especially in contradistinction to the Subcarboniferous ; in other words, 

 it is used as synonymous with the general term " Coal-Measures," somewhat in use. 

 2 1 F 



