152 PALEONTOLOGY OP NEW JERSEY. 



Formation and locality: In the dark micaceous clays beneath the Lowef 

 Green Marls at Haddonfield, New Jersey. Collection Acad. Nat. Sci., 

 Phila., where it was found in the tray with Leiostrica cretacea Conrad. 



LITTORINID^. 



Genus MODULUS Gmelin. 



Modulus lapidosa, n. sp. 



Plate XVII, Figs. 6-8. 



DelpMnula ? lapidosa (Mort.) Meek, Check List Cret. and Jur. Foss., p. 18; Geol. 



N. J., Newark, 1868, p. 738. 

 Straparolus lapidosus Gabb (in part): Jour. Acad. Nat. Sci., Phila., vol. 4, 2d ser., 



p. ,300, PL XLViii, Fig. 5; but not of Synopsis and subsequent publications. 

 Not DelpMnula lapidosa Morton: Sj'nop. Org. Rem. Cret., p. 46, PI. xix, Fig. 7, 



and Gabb's Synopsis, p. 48. 



Shell rather small, subdiscoid above, with a flattened or but slightly 

 convex spire, as seen in the internal casts, and a broadly rounded outer 

 margin to the .volutions and very shallow base. Volutions three or more, 

 rather rapidly increasing in size, the last one slightly spreading at the aper- 

 ture. Sutures very distinct. Umbilicus moderately large and the margin 

 sharply carinate; also showing a strong groove along the base on the inside, 

 indicating the existence of quite a strong spiral ridge on the inside of the 

 ajjerture of the shell just above the base. The aperture has been propor- 

 tionally large, higher than wide, obliquely subovate, rounded above and 

 pointed at the base of the iimer lip, with the spiral ridge as above described 

 just above the base; surface unknown. 



The casts of this species have the features of the genus DelpMnula, with 

 the additional one of the tooth-like ridge on the columellar lip a little above 

 its base. In this feature it agrees most nearly with the characters of the 

 genus Modulus Gmelin, and none of the other features yet known to belong 

 to it would disagree with those of that genus. I have before me casts of 

 fom* individuals more or less imperfect, but all showing in a satisfactory man- 

 ner the groove left by this tooth-like ridge and the angular base of the 

 aperture. For this reason I conclude to place this species under the genus 



