92 GEOLOGieAL REPORT. € 139 



a Pectwuculus, several Rostellariae, and numerous minute univalves being 

 superadded — many in a very fine state of preservation. The bald hilltops pi 

 Chickasaw, as well as, for instance, an outcrop of gray sandy marl on Cherry 

 Creek, near the P. <>. of that name, furnish abundance of two small species of 

 Hemiaster (about :! , of an inch in diameter), winch I have not thus far observed 

 in Tippah county, in whose marls and limestone Radiata are very rare. They 

 oocur, however, associated with Baailit^ Tippaensis, Crassatella Tippana.. and 

 other unquestionable Owl Geek fossils. 



139. Fossils of the Ripley Group.- 1 give below a List of 

 the fossils thus far collected by myself from the strata of the 

 Ripley Group in Tippah, Pontotoc and Chickasaw, naming, 

 o'encrically, as far as the limited time at disposal allowed of their 

 determination, those which could not be identified with species 

 heretofore described. (See "J 128 ; note.) 



1 have to regret that at the time of preparing this list, in which I have been 

 kindly aided by Frof. W. D. Moore, the latest publication of Mr. Conrad on this 

 subject (Jour. Acad. Nat. Sc. Phila., Vol. IV, n. s., pp. 275-291) had not come 

 to myjiands ; for which reason, a part only of the new species there described 

 by him (which have since been identified by Prof. Moore) will be found in this 

 catalogue, although no doubt, several more of the undetermined species are 

 described in the paper referred to. I shall, therefore, mention separately the 

 species named by Mr. Conrad, found in Tippah county by Dr. Spillman, but 

 not thus far identified with specimens in the collection of the Survey. — 

 Species marked with an asterisk (*) have thus far been found only in the 

 uppermost crystalline limestone. 



I subjoin also the interesting comparative list of the fossils of Tippah, Xew 

 Jersey and Eufaula, Alabama, (prepared by Mr. Conrad, assisted by Mr. Wm. 

 M. Gabb), given in the place above referred to ; to which I would add that in 

 1856, I identified at least % of a collection, made by Tuomey, of fossils from 

 the crystalline limestones and blue marls of Chunnenugga Ridge, Macon county. 

 Alabama, with species previously found by myself on the territory of the Ripley 

 Group in Mississippi. It thus appears that the beautiful and singular fauna 

 represented by this group, is much more widely diffused than was at first sup- 

 posed, and is well connected by transitions with other stages of the Cretaceous. 

 The unusually large proportion of univalves as compared with bivalves, no less 

 than many of the forms of both classes of Mollusca, are strongly suggestive of 

 the approach of the Tertiary epoch, to whose strata as developed in Mississippi, 

 those of the Ripley Group bear an extraordinary lithological resemblance. The 

 very perfect state of preservation of the fossils, also, is somewhat startling at 

 Irst sight, and instinctively recalls to mind the beds of the Tertiary. 



CEPHALOPODA. 



Ammonites placenta, Mort. Scaphites Conradi, Mort. 



Ammonites syrtalis, Mort. ? Scaphites Iris, Co.v 



