OF THE UNITED STATES. 77 



Scutella, Lam. 



1. crustuloides, (S. G. M.) PI. xv, fig. 10. 



Specific character. Orbicular, centre elevated, margin thick; 

 five short, sub-elliptical ambulacra. 



Diameter, from a fourth of an inch to near an inch. 



This species is very distinct from any I have met with, 

 recent or fossil. It is found in considerable numbers in 

 the calcareous strata of South Carolina. 



2. S. Lyelli, (Conrad.) PI. x, fig. 8. 



3. S. Rogersi, (S. G. M.) PL xiii, fig. 3. 



Specific character. Subovate or suboval, slightly convex ; 

 posterior margin truncated ; ambulacra slightly prominent, 

 open at the marginal extremities; apex central; beneath 

 slightly concave, with five simple, compressed lines, corres- 

 ponding to the ambulacra; anus near the posterior end, one- 

 sixth of the distance from the posterior margin to the mouth. 



Common in the newer cretaceous strata of Monroe 

 county, Alabama. T. A. Conrad. 



I have much pleasure in naming this beautiful species 

 after my kind friend Henry D. Rogers, Esq. 



Spatangus, Lam. 



1. S. parastatus, (S. G. M.) PI. iii, fi^. 21. 

 Amer. Journ. Science, vol. xiii, pi. iii, fig. 10 and 11. 



Specific character. Five excavated ambulacra, the posterior 

 one extending to the base, the other four to the margin ; poste- 

 rior end remarkably elevated. 



Length, one inch. 



