MIOCENE MOLLUSCA AND CRUSTACEA. 119 



Formation and locality: In the fine gray micaceous Miocene marls near 

 Shiloh, N. J., but more abundantly near Jericho, N. J., in the same position. 

 From the collections at the National Museum and at New Brunswick, N. J. 



Natica (Lunatia) heros. 

 PI. xxii, figs. 9 and 10. 



Natica heros Say: Jour. Acad. Eat. Sei. Phila,, 1st ser., vol. 2, p. 248; Am. Jour. 



Conch.; Emmons, Geol. Surv. N. Carolina, 1852, p. 267, tig. 149, and p. 265. 

 Not N. heros Tuomey and Holmes, Plioc. Foss. S. Carolina, p. 114, PI. xxv, fig. 15, of 



Gould and other authors. 

 ? Lunatia catenoides (Wood) Conrad: Proc. Acad. Nat, Sci. Phila., 1862, p. 565; Meek, 



Check List Miocene Foss., p. 19; Heilprin, Proc. Acad. Nat. Sci. Phila., 1887, 



pp. 397 and 404. 



Mr. Say's original description of his Natica heros, as given in the Jour- 

 nal of the Academy of Natural Sciences, Philadelphia, is as follows: "Shell 

 suboval, thick, rufo-cinereous; -within whitish; columella incrassated; callous 

 not continued over the lower part of the umbilicus, hardly extending beyond 

 a line drawn from the base of the columella to the superior angle of the 

 labrum; umbilicus free, simple." 



Among the naticoid shells from the New Jersey Miocene there are 

 several which have so precisely the aspect of the young shells of L. heros 

 of our Atlantic coast that it is impossible to distinguish between them. And 

 if it is considered that in taking specimens of that shell of similar size 

 from a number of localities, as I have done, and that they vary greatly 

 in their characters, it becomes all the more difficult to draw any line of dis- 

 tinction between the fossil shells under question and the living forms. It 

 is true that specimens of L. heros often are less oblique than the New Jersey 

 fossil forms, and that others may be found having the upper volutions more 

 distinct and rounded above, but there are many others where the obliquity 

 of the volutions pass on the other side of those of the fossil specimens, so 

 that in examining L. heros from a large number of localities I have reached 

 the conclusion that no specific distinction exists. 



Mr. Conrad, in his list of Miocene fossils, Proceedings of the Academy 

 of Natural Sciences, Philadelphia, 1862, adopts the name L. catenoides, 



