750 SYSTEMATIC PALEONTOLOGY 



and condyle, but all the specimens lack the outer points. All of the frag- 

 ments are nearly straight with slight taperings and are covered with rows 

 of straight granules closely joined so as to impart a fluted appearance to 

 the spines. The larger spines show twelve or more such lines. 



Dimensions. Length of longest specimen 1-i mm., diameter of spine 

 2.5 mm. 



Occurrence. EANCOCAS FORMATION. South side of Appoquinimink 

 Creek between Odessa and mill-dam, Delaware. 



Collection. Maryland Geological Survey. 



Family CASS1DULIDAE 



Genus CASSIDULUS Lamarck 



CASSIDULUS sp. 



Description. Test small, elevated, slightly truncated at the posterior 

 end ; upper surface very convex, sides nearly straight, ends rounded ; under 

 surface nearly flat but much broken. Ambulacral areas narrow. Apical 

 system small, slightly anterior of the center. Peristome lacking. Peri- 

 proct small and a long shallow sulcus. 



Dimensions. Length 12 mm., width, 9.5 mm., height 7 mm. 



The single specimen of this form that has been found has the lower 

 surface badly damaged, but there is little doubt that it is a representative 

 of the genus Cassidulus so widely found in Upper Cretaceous strata farther 

 south. It is, however, quite distinct from any other known species, but 

 because of its fragmentary character it seems unwise to give it a name at 

 the present time. 



Occurrence. MONMOUTH FORMATION. Bluff northeast of mouth of 

 Turner's Creek, Cecil County, Maryland. 



Collection. Maryland Geological Survey. 



Family ECHINOCORYTHIDAE 



Genus CARDI ASTER Forbes 

 CARDIASTER MARYLANDICA n. sp. 



Plate XLVII, Figs. 6-10 



Description. Test small, cordate, with pronounced anterior grooves; 

 upper surface slightly convex, lower surface flat. Ambulacra wide. Apical 



