40 CONRAD'S DESCRIPTIONS OF NEW EOCENE FOSSILS. 



HOLASTER, Agas. 



H. MoRTONi. PI. 1, fig. 10. — Oval; conico-convex ; apex nearest the posterior margin ; dorsal furrow 

 terminating some distance from the apex ; ambulacra! furrows not deeply impressed ; pores of 

 ambulacra transversely ova], the series gradually diverging from the apex, and suddenly converging 

 towards the opposite extremity ; tubercles of the disk small ; margin obtusely rounded ; mouth situated 

 about one-third the distance of length from the anterior extremity ; central ridge of the base prominent. 



Locality. Palmyra, Lee county. 



NUCLEOLITES, iaw^. 



N. MoRTONi. PI. 1, fig. 11. — Obtusely subovate, anteriorly convex, posteriorly flattened ; ambulacra wide, 

 rapidly narrowing towards the apex; base concave; posterior margin truncated ; anus supra-raarginal, 

 transversely oblong. 



Locality. Palmyra, Lee county. 



A cast from the Burr-stone, remarkable for its very oblique flattened disk posterior 

 to the apex. Dedicated to Dr. S. G. Morton. 



N. Lyelli. PI. 1, fig. 14. — Oval, depressed; dorsal line slightly contracted and parallel v.'ith the base; 

 anus transversely oblong, on a line with the end margin, which is slightly emarginate; base excavated 

 about the mouth. 



Locality. Baker county. 



A cast from Burr-stone. Dedicated to the eminent geologist Sir Charles Lyell. 



DISCOIDEA, Agass. 



D. Haldemani. pi. 1, fig. 12. — Oval, convex-depressed ; ambulacral outlines wide, slightly converging 

 towards the inferior extremities ; the inner pairs subrectilinear and slightly diverging from the apex to 

 the inferior extremities; periphery rounded, and having an undulated outline; anus small, round ; 

 mouth subcentral, transversely elliptical ; base between the anus and the posterior margin somewhat 

 concave ; anteriorly slightly convex. 



Locality. Bainbridge, Baker covmty. 



Mr. Couper's note, accompanying this species, informs us that it is from limestone 

 dug out of a well seventy feet beneath the surface. The specimens are mineralized 

 crusts, one of which is nearly perfect. 



CIDARITES, Lam. 



C. MoRTONi. PL 1, fig. 13. — Globose, granulated; series of tubercles distant. 



Locality. New Palmyra, Lee County. Dr. Mercer. 



The fragment frotn which the figure has been drawn is well preserved, and very 

 distinct from the other American species of Cidarites. The small tubercles 

 encircling the mammillEe are somewhat oval or suborbicular in form, and irregularly 

 disposed, or inclining to a double and alternating series. 



