paljEological report or geological survey. 487 



Geological position and locality. Found in the limestone about five 

 feet beneath the Devonian black slate, and above the beds of Hydraulic 

 cement-stone, Jefferson county, and in the same geological position on 

 the falls of the Ohio. It does not appear, from what is known of it, 

 to have a very great vertical range, probably not more than three or 

 four feet. 



OLIVANITES VERNEUILII. Troost. 



Ref. and Syn. Pentremites Verneuilii, Troost, sixth report on the Ge- 

 ology of the State of Tennessee, Nashville, 1841. Pentremites Verneui- 

 lii {Beadle) d 'Orbigny Prodrome de Pal, Slratigr 1, p. 102. 



Elceacrinus Verneuilii Roemer. Monographic der Fossilen Cri- 

 noiden familie der Blastoideen, &Tc., Berlin, 1852, p. 59. 



This fossil is found in great abundance in rocks of the Denovian 

 period, at the Falls of the Ohio river, and on Beargrass creek near 

 Louisville, Jefferson county, Kentucky, and in other localities. 



Professor Troost distinguished this fossil in 1841, as Pentremites 

 Verneuilii. In a list of fossil crinoids of Tennessee, published in the 

 proceedings of the American Association for the Advancement of 

 Science ; of the meeting held at Cambridge, Boston, 1850, the learned 

 professor has removed it from Pentremites ; having erected a new genus 

 for its reception, and distinguished it as Olivanites Verneuilii. In a 

 private letter, written August 3d, 1849, to a distinguished lady of 

 Tennessee, Professor Troost removes Pentremites Verneuilii to Olivani- 

 tes. 



Dr. Fred. Roemer, in an elaborate and able work on the Family 

 Blastoidea, referred to above, has re-described this fossil'under the 

 generic title of Eloeacrinus, (retaining Prof. Troost's specific name,) 

 with excellent figures by Hugo Troschel. For want of well preserved 

 specimens, both the figures and description are defective in many res- 

 pects. 



For these reasons, and possessing quite perfect specimens, it is pro- 

 posed to describe these, and restore the name proposed by that pioneer 

 of western geology, Dr. Troost. 



During the last seventeen years hundreds of these curious forms, 

 known as "Petrified Hickorynuts," have passed through our hands, 

 having been distributed to collectors at home and abroad. Dr. Roe- 



