526 CRETACEOUS PALEONTOLOGY. 



Formation and locality. Navesink marl, Atlantic Highlands 

 (108), near Crawfords Corner (i26 7 ), near Walnford (Whit- 

 field), near Arneytown (Morton). 



Geographic distribution. New Jersey. 



Super-family POROMYACEA. 

 Family FOROMYACIDAE. 

 Genus LIOPISTHA Meek. 

 Liopistha protexta (Conrad). 

 Plate LVIII., Figs. 4-6. 



1853. Cardium protextum Con., Jour. Acad. Nat. Sci. Phil., 

 2d ser., vol. 2, p. 275, pi. 24, fig. 12. 



1860. Fragilia protexta Con., Jour. Acad. Nat. Sci. Phil., 2d 



ser., vol. 4, p. 275. 



1 86 1. Papyridea elegantula Gabb, Synop. Moll. Cret. Form., 



pp. 164, 218 (108, 162). 

 1864. Papyridea (Liopistha} protexta Meek, Check List Inv. 



Foss. N. A., Cret. and Jur., p. 12. 

 1868. Liopistha protexta Con., Cook's Geol. N. J., p. 726. 



1875. Liopistha protexta Con., Kerr's Geol. N. Car., App. p. 28. 



1876. Liopistha protexta Meek, Inv. Cret. and Ter. Foss. Up. 



Mo., p. 227, text figures 20-24. 

 1886. Leiopistha protexta Whitf., Pal. N. J., vol. i (Monog. 



U. S. G. S., vol. 9), p. 140, pi. 20, figs. 1-3. 

 1886. Leiopistha inflata Whitf., Pal. N. J., vol. I (Monog. U. 



S. G. S., vol. 9), p. 142, pi. 20, figs. 6-7. 

 1905. Leiopistha protexta Johns., Proc. Acad. Nat. Sci. Phil., 



1905, p. 13. 



Description. The dimensions of a large individual are: 

 length, 30.5 mm.; height, 22 mm.; thickness, 16.5 mm. Shell, 

 exclusive of the projecting beaks, subelliptical in outline. Beaks 

 prominent, situated a little in % advance of the middle of the shell, 

 their apices pointed, incurved and nearly in contact. Antero- 

 cardinal slope slightly concave; anterior margin sharply 

 rounded; basal margin regularly convex throughout; posterior 



