290 



NORTH-CAROLINA GEOLOGICAL SURVEY. 



trie striae ; umbo flattened ; apex sub-acute ; inner margin 

 entire. One of the most common fossils of the shell marl. 



U. GIBBESII : TUOMET & HOLMES, FOSSILS OF SOUTH-CAROLINA J p. 



(Fig. 215.) 



74. 



FIG. 215. 



&quot; Shell somewhat triangular, thick, con 

 centrically furrowed ; buccal side rounded; 

 anal side somewhat beaked, angular, with 

 a longitudinal ridge ; umbones incurved ; 

 lunule somewhat excavated.&quot; 



In addition to the foregoing, I may add the following as 

 common in the IS&quot;orth-Carolina shell marl beds : Crassatella 

 alta. 0. Marylandica, C. Protexta, C. Melina. 



FAMILY CYCLASIDAE. CORBICULA DENSATA. CYRENA DENSATA. 



CON. (Fig. 21 5 A.) 



FIG. 2ioA. Shell orbicular striated concen 



trically, polished, lateral teeth 

 elongated. 



This shell is very abundant at 

 the miocene marl bed of Mr. 

 Flower, on the Cape Fear. 



FA1SSLY CORBULIDAE. CORBITLA CU- 

 NEATA. (Fig. 215B.) 



Shell small, thick, ovate, con 

 centrically striate ; anterior margin rounded : 

 posterior elongated, or somewhat rostrate. 

 Common in the shell marl. 



&amp;gt; IG. 21 OB. 



FAMILY LUCENIDAE. 



This family have orbicular shells, both free 

 and closed with hinge teeth, somewhat varia 

 ble as one or two laterals, or one and one, 

 ;iud the other obsolete ; pallia! line simple, muscular im 

 pressions two, elongated and rugose. The family is princi 

 pally composed of tropical and temperate species, and live 



