(F.) 



DESCUIPTrONS OF NEW SPECIES OF FOSSILS 



FROM THE DEVONIAN ROCKS OF IOWA. 



By JAMES HALL & R. P. WHITFIELD. 



PKELIMINARY NOTE OX THE GEOLOGICAL FORMATIOXS. 



During the progress of the Geological Survey of Iowa, from 1855 to 

 1860, a considerable amount of material, in the way of iact.s, maps and 

 sections, was accumulated, beyond and after that which Mas emliraced 

 in the volumes published in 1858. The cessation of the work of the 

 survey left the materials on hand.* 



The collections of fossils, v^diich had been made in the Devonian 

 rocks and sent to the principal geologist, were so meagre that no satis- 

 factory account of the pafoontology of the formations could be given. 

 No subdivision of the beds had been noticed, and the fossils were all 

 communicated as coming from the same formation, and were at that 

 time referred to beds of the age of the Hamilton group. 



Subsequently, more considerable and important collections, in num- 

 ber of species, were contributed by Mr. O. H. St. John, residing at 

 "Waterloo. While these collections added much to our knowledge of 

 this ancient fauna, they were not sufficient to clear up some points in 

 doubt, and in 1866 Mr. R. P. Whitfield undertook an exploration of 

 the principal localities of the region. 



While making the collections of fossils from some of the rock forma- 

 tions of north-eastern Iowa, in localities previously considered of the 

 age of the Hamilton group of Kew York, his attention was attracted 

 to the peculiar grouping of organic remains, and to the great numbers 

 of species which were known or believed to be characteristic of other 

 formations ; — as for example, at Waterloo, on Cedar Eiver, where the 

 formations are chiefly marked by the assemblage of fossil corals and 

 Stromatopora, abundant at the quarries and along the banks of 



* The Legislature of Iowa, after receiving and distributing tlie volumes published 

 n 1858, and with the evidence of progress before them in a printed supplement, with 

 maps, sections, etc., of portions of the coal field, prepared for publication, not only 

 refused to publish or go on with the field work, but refused to refund to the princi- 

 pal geologist the salaries of his assistant and expenses of the survey for the preced- 

 ing year, which he had advanced from his own means, or to pay for his own services 

 during that time; all of which to this day remains unpaid. — J. H. 



