Descriptioxs of Devoxian Fossils. 225 



At "Waverlv, twelve or fifteen miles north- west of AYaterloo, the 

 same beds occur, holding nearly the same series of fossils as that at 

 Independence. 



From the foregoing facts, we should infer that the Waterloo beds 

 are more nearly related to the Upper Ilelderberg limestones of New 

 York, while those of Independence and Waverly may be representa- 

 tive of the New York Hamilton, At Cedar Falls, between Waverly 

 and Waterloo, the AVaverly beds are exposed, and above them are 

 groups of strata which are referred by Mr. Worthen to the Chemung 

 group. (See Geol. Iowa, Yol. I, pt. 1, p. 310.) 



Near Rockford, in Floyd county, on the west branch of Lime creek, 

 there is a series of beds outcropping, a section of which is given on 

 page 309 Geological Report of Iowa. Near the base of this section 

 there is a thin bed of calcareous sandstone, containing the characteristic 

 Chemung fossil Spirifera disjuncta Sow., in considerable numbers. 

 Above this bed is a heavy layer of white limestone, in which occur 

 large quantities of Stromatopora, forming extensive layers of many 

 feet in extent, and often three or four feet in thickness, with but slight 

 interruptions of shaly matter. Further up the bank there is a bed of 

 calcareous clay of considerable thickness, formed in part, at least, by the 

 decomposition of a bed of pyritiferous argillaceous limestone, which 

 occupies the top of the cliif, and contains great numbers of beautiful 

 fossils. Among them we find two species of Stromatoporoid forms 

 belonging to the genus Csenostroma of Winchell, and one w^hich is 

 referable to Caunopora of Phillips. Of the corals, a species of Pachy- 

 phyllum {P. Woodmani of this paper, Smithia Woodmani White, 

 Geol. Rep. Iowa, ISTO, vol. 1, j). 1S8), is the most abundant, and, so 

 far as we are aware, is the first species of the Pachyphyllum recognized 

 in this country. A second species of the genus, and a number of 

 other Cyathophylloid corals, all of which are undescribed, are common. 

 These species being new, have, therefore, no stratigraphical significance ; 

 but among the Brachiopods there are several which may be considered 

 as forms characteristic of the Chemung group, or as close representative 

 species of that formation. Of the former, we may mention Orthis 

 impressa, Stropjhodanta perplana var. nervosa, Atrypa hystrix and 

 Cryptonella Eudora - : of the latter, Strophodonta reversa, S. arcuata 

 Sind Sj/irif era Whitneyi — representing Strophodonta ccelata, Stropho- 

 donta cayuta and Spirifera disjuncta of the Chemung group in New 

 York. 



At a point eight miles above Rockford, known as Hackberry, there 

 is another outcrop of the same beds, containing the same fossils, with 



[* An examination of other specimens of the form referred as above, has proved it 

 to be a distinct species, for which the name C. Calnni is proposed.] 



[Assem. No. 133.] 20 



