MTOCENE MOLLUSCA AND CRUSTAdEA. 119 



Formation and local iti/: 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) heeos. 

 PI. XXII, figs. 9 and 10. 



Naticn heros Say: Jour. Acad. Nat. Sci. Phila., 1st ser., vol. 2, p. 248; Am. Jour. 



Couch.; Amnions, Geol. Saw. N. Ciutdina, 1852, j). 2(j7, tig. 149, aud p. 2(515. 

 Not A", heros Tuoiney and Holmes, Plioc. Foss. S. Carolina, ]i. 114, PI. xxv, tig. 15, of 



Gould and other authors. 

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



Check List Mioceue Foss., \k 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; witliiii whitish; cohonella inci'assated; callous 

 not continued over the lower part of the umbilicus, hardly extending be}'ond 

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

 labrum; nnihiUcns free, simple." 



Among the natii'oid shells from the New Jersey Miocene there are 

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

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

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

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

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

 tinction l)etween the fossil shells under qviestion 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, 



