514 Systematic Paleontology 



Lepehditia elongata Weller 

 Plate XCVII, Fig. 11 



Leperditia elongata Weller, 1903, Geol. Surv. N. J., Pal., vol. iii, p. 259, pi. 

 xxiii, fig. 13. 



Description. — " Carapace large, obliquely subreniform, posterior ex- 

 tremity the highest. Dorsal margin straight, two-thirds of the total 

 length of the valves, its extremities obtusely angular. Anterior margin 

 obliquely truncate from the hinge-line, sharply rounded in front into the 

 broadly convex ventral margin, which, in turn, curves regularly into the 

 nearly semicircular posterior margin. Eye tubercle distinct, situated a 

 little above the middle of the antero-dorsal quarter of the valve. Both 

 anteriorly and posteriorly the margin is slightly flattened in a rather in- 

 distinct marginal border, extending from the extremities of the hinge-line 

 to the middle of the valve. Surface smooth. 



" The dimensions of an average specimen are : Length 12 mm. ; height 

 G.5 mm.; convexity of one valve 2.5 mm." Weller, 1903. 



Occurrence. — Heldeeberg Formation, Iveyser Member. Tonoloway. 



Collection. — U. S. National Museum. 



Leperditia gigantea Weller 



Plate XCVII, Fig. 10 



Leperditia gigantea Weller, 1903, Geol. Surv. N. J., Pal., vol. iii, p. 260, pi. 

 xxiii, fig. 14. 



Description. — " Carapace very large, subreniform in outline. Dorsal 

 margin straight, about three-fifths of the total length of the valve, its 

 anterior extremity obtusely angular, its posterior extremity rounding into 

 the nearly semicircular posterior margin. Ventral margin gently convex, 

 anterior margin broadly rounded, nearly as high as the posterior margin. 

 Eye tubercle distinct, situated at about the middle of the antero-dorsal 

 quarter of the valves; behind the eye tubercle there is a broad, shallow, 

 indistinct, flattened sulcus, which extends downward from the hinge-line 

 nearly to the center of the valve. The antero-dorsal angle is distinctly 

 compressed, and the flattened area extends around the anterior margin as 

 a marginal border. The posterior margin is also bordered by a more or 

 less distinct, flattened border. Surface smooth. 



