122 PALEONTOLOGY OF NEW JERSEY. 



frequently shows on part of a volution only, while on the remaining parts 

 the callous portion is preserved. In the form and proportion of the callus 

 in the umbilicus the same variations are seen that show on the living* shells. 

 Formation and locality: In the gray micaceous marls of the Miocene at 

 Shiloh and Jericho, N. J. From the collections of the National Museum. 



Family CALYPTR.EID.E. 



Genus CRUOIBULITM Selinm. 



Grucibulum costatum. 



PI. xxn, figs. 11-14. 



Calyptrcea costata Say: Am. Jour. Sci., 1st. ser., vol. 2, p. 40. 



Bispotcea costata Say: Jour. Acad. Nat. Sci., Phila,, 1st ser., vol. 4, p. 132; Conrad, 

 Miocene Foss. p. 79, PI. xiv, fig. 2. 



Crucibulum (Dispotcea) costatum Conrad: Proty Acad. Nat. Sci., Phila.. 1862, p. 568, 

 where he cites Silliman's Journal, vol. 11, p. 40, instead of vol. 2, p. 40, typo- 

 graphical error by using figures in place of Roman numerals. 



Grucibulum costatum Meek: Check List Miocene Foss., p. 15; Heilprin, Proc. Acad. 

 Nat. Sci., Phila., 1887, pp. 390 and 404. 



Calyptrcea pileolus H. C. Lea: Trans. Am. Phil. Soc, vol. 9, 22, PI. xxxv, fig. 38. 



Grucibulum dumosum Tuomey and Holmes, Plio. Foss. S. Carolina, p. 109, PI. xxv, 

 fig. 6, and not their (J. costatum, 



f Hipponyx BuUii Tuomey and Holmes, loe. cit., p. 112, PI. xxv, fig. 13 and 13a, Inner 

 cup only. 



"Oval, convex, with numerous slightly elevated, equal equidistant 

 costse, and crowded obtuse, concentric lines, which are regularly undulated 

 by the costse; apex mamillated inclined to one side; inner valve patelliform, 

 dilated, attached by one side to the side of the shell, acutely angulated at 

 the anterior junction, and rounded at the posterior junction, and rapidly 

 tapering to an acute tip, which corresponds with the apex of the shell." 

 (Say in American Journal of Science, loc: cit.) 



Different specimens of this shell vary greatly in the degree of elevation, 

 in the number and strength of their ribs, in size and in the form of the inner 

 cup or process. This latter feature is perhaps the most perplexing one of 

 the species, being in some cases a complete cup atta died along a narrow 



