4 POST-PLEIOCENE FOSSILS. 



We retain the characteristic specific name ampla for this variety, which was suggested 

 by our friend, Prof. Agassiz, and give in the plate, fig. 6, a good figure of this magnificent 

 mellita, surrounding it with an outline (6a.) of the largest specimen yet discovered. 



Plate I. Fig. 6, View from above. 



" 6a, Outline of largest specimen in the cabinet. 

 " 6b, Profile of same. 



Locality. Simmons' Bluff, St. Paul's: 



Museum, College of Charleston; Cabinet F. S. H. 



ECHINUS V A R I E G A T U S . 

 Plate II. Fig. 1. 



Echinus variegatus, Lam., An. sans Vert., 2d Ed., Vol. 3, p. 365. 



Echinus variegatus, Sag, Jour. Acad. Nat. Sci., Vol. 5, p. 226. 



Echinus variegatus, L. R. Gibbes, Tuomey's Geol. So. Ca., appendix, p. xxiii. 



Description. Shell, orbicular, sub-globose, the large tubercles extend in rows from 

 basal to dorsal aperture; lower surface, or base, closely covered with rows of large mam- 

 maliferous tubercles, varying slightly in size; plates studded with small tubercles, giving 

 the shell a beautiful granulated appearance; the pores in the series of ambulacral bands 

 are placed alternately two and four, and the rows slightly inclined; aperture for the 

 mouth large, circular, with ten fissures or clefts, which are narrow, deep and slightly 

 curved ; dorsal aperture irregular ; spines short, and numerous, the larger ones subtrun- 

 cated at their points ; a few spatula-like spines surround the mouth. 



This species is living in deep soundings off the Carolina coast, and is known as the 

 short-spined sea urchin, or bachelor's button. Like its congener, only one specimen in a 

 perfect state has, as yet, been obtained from the Post-Pleiocene ; the fragments and spines 

 are numerous. 



Plate II. Fig. 1, Shell, natural size, viewed from above. 

 " la, Spines. 



Locality. Simmons' Bluff, St. Paul's; Charleston. 



Museum, College of Charleston ; Cabinet F. S. H. 



