126 [June, 



We are under obligations to Prof. James Hall, of Albany, New York, for 

 the free use of his extensive collection of books on Palaeontology, as well as 

 for occasional sugestions while investigating the Nebraska fossils, described in 

 this and our former papers. 



Correction. 



In a paper communicated by us to the Academy in March last, and published 

 in the preceding number of the Proceedings, we referred to the genus Pyrula 

 a shell (P. Z?a!rf/f, page 66), which we have since satisfied ourselves belongs 

 more correctly to the genus Busycon of Bolten ;. we now change the name to 

 Bmycon Bairdi. 



Ceratites Americanus. 

 By Professor L. Harper, University of Mississippi. 



The Ceratites, a Cephalopodus mollusk, subgenus of Ammonites, has been 

 discovered in Europe long ago. All the European species, without any excep- 

 tion, belong to the new red sandstone or Triassic formation. Twenty-one species 

 have, according to Bronn, been placed in the St. Cassian formation in Tyrol, to 

 which the lowest place in the Trias has most probably to b^i assigned. One 

 species is found in the St. Cassian rocks and also in the Muschelkalk ; one in 

 the Bunter sandstein and the Muschelkalk, and of the remaining eight species, 

 three belong certainly and five probably to the Muschelkalk of the Trias. The 

 Cerrttiips were therefore considered as characteristic, and belonging exclusi^-ely 

 to the nciv red sandstone formation, and exclusively a European fossil, until a 

 few years ago L. V. Bach, the late great German Geologist, discovered a Cera- 

 tites in the cretaceous rocks of the Caucassus, which he called Ceratites Syriacus. 

 No species of the Ceratites has heretofore been found on the continent of Ame- 

 rica. 



About three years ago, in summer, 1853, when I was in the State of Alabama, 

 I examined the bed of the Tuscaloosa or Black Warrior River, near the little 

 village of Erie in Greene County, about 12 miles above the confluence of the 

 Tombigbee and Black Warrior rivers, between the 32d and 33d degrees of north 

 latitude, where the river cuts through the lowest part of the cretaceous forma- 

 tion of our southern State^", corresponding most probably to the Turonien ot 

 D'Orhigny. The bluff of the river consists here entirely of different strata of 

 green sand, divided in several parts by thin seams of a hard co' glomerate of 

 peroxide of iron and green sand, and is from 50 to 95 feet high. The river was 

 then unusually low, and more than one-half of its bed perfectly dry and acces- 

 sible. 



On a sand-bank in the middle of the river, immediately below a very deep 

 place, were found, among other evidently cretaceous fossils, three specimens of 

 a smalJ Ammonite, which, after a careful examination, I immediately recognized 

 to be a species of Ceratites, in which opinion I was later confirmed by as high 

 an authority as Prof. L. Agassiz, of Cambridge, who pronounced it to be a new 

 species of Ceratites, closely allied to Ceraticus Syriacus of L. V. Btich. 



This bfiog the first Ceratites ever found on the continent of America, I pro- 

 pose for it the name of 



Ceratites americanus. 



Testa compressa, disco baud dissimili, paulisper deneata ad aperturam, val- 

 deque at.tenua'a ad apicern, et pra3cipue subito accrescente a medio usque ad 

 apenuram; aufractibus duabus, secundo amplecto primi ventre et tanquara in 

 Btriam posito ; apertu-a semi-ovata ; loborum numero, in vita, sex, toti- 

 demquf sidhe, loho ventrali attamen nonnihil indistincto ; lobis dentibus tribns 

 raunitis, qui magnitudinis causa etiam lobi secundarei vocarentur; septis angu- 

 larihus dorso relrorsum flexis ; siphunculo dorsali. 



The two specimens, still in my possession and here represented, are both very 



