ART. 10 CEETACEOUS FAUITAS OF THE CAEOLINAS STEPHENSON 19 



sharply pointed posteriorly, and has a more sharply defined umbonal 

 ridge than G. carolinana. The hinge characters of the two species 

 also differ in detail. 



Localities. — From Pender County at the new Rocky Point quarries, 

 a mile northeast of Rocky Point station, and at French Brothers' 

 quarry at old Rocky Point, 3 miles east of Rocky Point station; 

 from the Castle Hayne quarries in New Hanover County, N. C. The 

 type was collected by L. B. Kellum in 1923. 



Geologic position. — Upper Cretaceous, upper part of Peedee for- 

 mation, upper part of Exogyra costata zone. European equivalent, 

 upper Senonian (Maestrichtian) , 



Type 'material. — The type material is in the United States Na- 

 tional Museum. Holotype, Cat. No. 73438. Paratypes Cat. Nos. 

 31750-31752, 73439. 



CARDIUM (TRACHYCARDIUM) PENDEEENSE Stephenson 



Plate 6, figs. 5-8, Sa 



1823. Cardium {TrachyGardium) Tpenderense Stephenson, Nortli Carolina Geol. 

 and Econ. Survey, vol. 5, pp. 291-292, pi. 71, figs. 1-3. 



Description. — The type of this species is an imperfect external 

 mold from French Brothers' quarry at Old Rocky Point on Northeast 

 Cape Fear River, now known as Lanes Ferry, 3 miles east of Rocky 

 Point station, Pender County, N. C. The additional material now 

 available for study includes numerous internal casts and some 

 imperfect external molds, collected by W. B. Clark at the old quarry 

 in 1888, and not previously examined by me, and a collection made 

 by L. B. Kellum in 1923 at the new quarries a mile northeast of 

 Rocky Point station, including 7 left and 9 right valves, some of 

 which are nearly complete, and 3 internal casts. The original de- 

 scription should be consulted before reading the following supple- 

 mental description. 



The more complete new material shows the number of ribs to be 

 48 or 49 instead of 45, The individuals show considerable variation, 

 ranging in outline from a little longer than high to considerably 

 higher than long. These differences may be due in part to mechani- 

 cal deformation in the sediments, but I am inclined to regard them 

 as chiefly original individual variations, or perhaps in part as sex 

 differences. The ribs appear to be identical in the different forms, 

 and there is no suggestion that more than one species or even variety 

 is represented. The ribs on the anterior slope near the margin 

 exhibit rather coarse transverse rugosities. Some of the specimens 

 show marked resting stages in growth at wide intervals, while others, 

 even large ones, exhibit continuous even growth. The beaks are 

 almost direct or very slightly prosogyrate, instead of opisthogyrate 



