492 PAL.EONTOLOGICAL REPORT OF GEOLOGICAL SURVET. 



Greatest width of interradial pieces, - - . T y-o inch. 



Greatest length of interradial pieces, - - 1-tVo inches. 



Greatest width of anal piece, - . T Vo- i ncn - 



Greatest leDgth of anal piece, ... l-iVo inches. 



Diameter of columnar pit, .... .^jul inch. 



Geological positiom and locality. — Found in rocks of the Denovian 

 period, about five or six feet below the hydraulic cement-beds, in a 

 rock of peculiar physical character, distinguished as the Olivanite bed ; 

 the bed varies in thickness from one inch to two feet. The space be- 

 tween the Olivanite bed and the hydraulic cement beds, abounds in 

 fragments of Spirifer cultrajugatus, and affords very few fossils, ex- 

 cept a few washed and rolled corals. The Olivanite bed is rather local, 

 although these fossils have a large horizontal range, the beds are in 

 interrupted patches. The beds at the Falls of the Ohio have proba- 

 bly been the most productive. They have also been found on Bear- 

 grass creek, Jefferson county, near Louisville ; on Silver and Fourteen- 

 mile creeks, Clarke county, Indiana ; and near Columbus, Ohio. 



OLIVANITES ANGULAKIS. Lyon. 



The preservation of the specimens of this species is such, that a 

 distinct oharacter cannot be traced of the fine external markings. The 

 general arrangement of the parts, however, are distinctly visible, war- 

 ranting the opinion, that the generic character is that of Olivanites, 

 although some of the parts are not distinctly preserved. 



Specific Character — Plate V. fig. 2, 2 a, 2 b. 



Description. — The body is sub-ovoid ; the diameter of the specimen 

 under consideration, from the anal side, transversely, to the highest 

 point on the opposite side, is . T \ 5 T of an inch ; the diameter parallel 

 with the flattened anal side .Jfo of an inch ; the height being .-^ of 

 an inch. The anal side between the pore pieces, on either side of it, 

 is nearly twice as wide as either of the other sides. The outline is 

 very much inflated on the line of the pore pieces, whilst the interra- 

 dials are deeply seated in the groove between them. The pseudambu- 

 lacral fields rise sharply angular from the interradial pieces, which are 

 much wider, and consequently have a much more rapid taper than the 

 same pieces in Olivanites Verneuilii. The pseudambulacral fields are 

 also narrower in proportion than in that species ; the summit and basal 



