120 POST-PLEIOCENE FOSSILS. 



Two small teeth of the collection, represented in figures 3, 4, of Plate XXVI, resemble 

 inferior teeth of the existing Carcharias Milberti? of our coast. The crown of the smaller 

 specimen has its lateral borders obscurely denticulate. The larger specimen has the base 

 of its crown widely expanded, and the lateral borders distinctly denticulate. The root in 

 both specimens, internally at the middle, is divided by a vertical sulcus. 



A single tooth, represented in figures 5 and 6 of Plate XXVI, belongs to the genus 

 Lamna. The crown is smooth externally, and slightly corrugated towards the base inter- 

 nally. On each side it is provided with a small uncinate denticle. The root is thick, 

 prominent, and divided by a sulcus at the middle internally; and has its extremities pro- 

 longed downward. 



Another tooth, represented in figure 7 of Plate XXVI, belongs to the genus Galeocer- 

 do. The anterior border of the crown is distinctly denticulated; the upper portion of the 

 posterior is feebly so, and the lower expanding portion coarsely. 



A minute tooth, represented in figure 8 of Plate XXVI, has a trilobate crown, with a 

 thick, quadrate root. 



The remaining specimens, of which several are represented in figures 9-14, of Plate 

 XXVI, appear to be symphysial and extreme lateral teeth. They have a conical, uncinate 

 crown, with an expanded base, and a wide, thick, trilobed root. We are unable to refer 

 them to any genus; perhaps they belong to Carcharodon. 



ISCHYRHIZA. — Leidy. 



I S C II Y E II I Z A M I R A . — L e i d y . 



Plate XXV. Pigs. 3-9. 



Ischyrhiza mira, Leidy, Proc. Acad. Nat. Sci. 



Ischyrhiza antiqua, Leidy, Proc. Acad. Nat. Sci. 



Ischyrhiza antiqua, Leidy, Emmons' Rep., N. C, Geol. Surv., p. 225. 



Teeth of a large sphyramoid fish have been discovered in the green sand formation of 

 New Jersey and Mississippi, and upon the Neuse river, North Carolina, which have been 

 referred to an extinct genus under the name of Ischyrhiza. Figures 3-8 of plate XXV, 

 represent the teeth of the same genus discovered in South Carolina. 



All the specimens which have come under the inspection of the author are imperfect, 

 except the one represented in plate XXV; nor have we been able to arrive at a positive 

 conclusion whether they indicate more than a single species. If they belonged to one 



