MOLLUSCA. 683 



Description. "Shell small or of medium size, with an elevated 

 spire which has an apical angle of from 40 to 45; volutions 

 four to five in number, very ventricose, with deep, well marked 

 sutures, which are slightly channeled on some of the specimens; 

 aperture round ovate, slightly pointed above and rounded below ; 

 rather less than half the length of the shell in casts or partially 

 exfoliated individuals; columella slender and solid, and in 

 the cast showing only a slight perforation from the removal of 

 the substance of the axis ; surface of the shell marked by fine im- 

 pressed spiral lines of punctations on the type specimen, but on 

 casts or partially exfoliated individuals this feature is not visible." 

 (Whitfield.) 



Remarks.: The generic reference of this species is by no means 

 certain. Pour specimens, including the type, are so labeled in 

 the collection of the Philadelphia Academy of Science, all of 

 which are from Mullica Hill, and all have the aperture incomplete. 

 The species somewhat resembles Lunatia halli, but it has a more 

 acute apical angle. The umbilical margin is rounded, as in the 

 casts of Lunatia halli, and the species should possibly be referred 

 to that genus. On the type specimen the shell is partially pre- 

 served, but the characteristic surface marking can be seen at 

 present only upon an area about i mm. wide by 3 mm. long. 



Formation and locality. Navesink marl, Mullica Hill (169). 



Geographic distribution. New Jersey. 



Genus GYRODES Conrad. 



Gyrodes abyssina (Morton). 



Plate LXXVIL, Figs. 7-9. 

 1834. Natica abyssina Mort, Synop. Org. Rem. Cret. Gr. U. 



S., p. 49, pl- i3 fi g- I 3- 

 1861. Gyrodes abyssina Gabb, Synop. Moll. Cret. Form., p. 115 



(S9)> 



1 86 1. Gyrodes Abbotti Gabb, Proc. Acad. Nat. Sci. Phil. 



(1861), p. 320. 



1864. Gyrodes Abbotti Meek, Check List Inv. Foss. N. A., 

 Cret. and Jur., p. 21. 



