G36 SYSTEMATIC PALEONTOLOGY 



LIOPISTHA PKOTEXTA Conrad 

 Plate XXXVI, Fig. 15 



Cardium, protextum Conrad, 1853, Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 



ii, p. 275, pi. xxiv, fig. 12. 

 Fragilia protexta Conrad, 1860, Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 



iv, p. 275. 

 Papyridea (Liopistha) protexta Meek, 1864, Check List Inv. Fossils, N. A., 



Cret. and Jur., p. 12. 



Liopistha protexta Conrad, 1868, Cook's Geol. of New Jersey, p. 726. 

 Liopistha protexta Meek, 1876, Kept. U. S. Geol. Survey, Territories, vol. 



ix, p. 227; text figs. 20-24. 

 Liopistha protexta Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, p. 140, 



pi. xx, figs. 1-3. 

 Liopistha inflata Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, p. 142, 



pi. xx, figs. 4, 5. 



Liopistha protexta Johnson, 1905, Proc. Acad. Nat. Sci., Phila., p. 13. 

 Liopistha protexta Weller, 1907, Geol. Survey of New Jersey, Pal., vol. iv, 



p. 526, pi. Iviii, figs. 4-6. 



Description. " Suboval or subtriangular, inequilateral, ventricose ; 

 ribs about twenty-eight in number, narrow, rounded, obsolete on the 

 posterior subraargin; posterior extremity obliquely truncated; beaks 

 prominent ; basal margin rounded ; umbonal slope undefined ; posterior 

 end gaping. (A cast.) " Conrad, 1853. 



Type Locality. Burlington County, New Jersey. 



Shell of moderate size and rather heavy for the genus, gaping pos- 

 teriorly, transversely ovate-trigonal in outline, evenly inflated, the maxi- 

 mum diameter falling near the medial portion of the shell; umbones 

 evenly rounded, the apices proximate, incurved and feebly opisthogyrate, 

 set a little in front of the median vertical and well up above the dorsal 

 margins; anterior and posterior dorsal slopes very gentle, the posterior 

 a little more produced and not quite so low as the anterior ; anterior end 

 well rounded, posterior end obscurely truncate; base line strongly and 

 symmetrically arcuate; external surface sculptured with twenty-six to 

 thirty-five angular radials, approximately uniform in size and spacing 

 over the medial portion of the shell, separated by slightly wider concave 

 interspaces; radials diminishing in prominence anteriorly but persistent 

 almost to the margin, evanescing much more abruptly posteriorly, leav- 



