MOLLUSCA. 693 



with a diameter of nearly 50 mm. The ridge which produces 

 this furrow in the casts seems to have increased in strength with 

 the growth of the shell, as it is less distinct in the smaller frag- 

 ments. 



Formation and locality. — Merchantville clay-marl, near Mata- 

 wan (loi), I^enola (163), near Burlington (Whitfield). 



Geographic distribution. — New Jersey, Mississippi, Alabama. 



Family TURRITBLLIDAB. 



Genus TurriteIvI,a Lamark. 



Turritella vertebroides Morton. 



Plate LXXVIIL, Figs. 14-17. 



1834. Turritella vertebroides M'ort, Synop. Org. Rem. Cret. Gr. 



U. S., p. 47, pi. 3, fig. 13. 

 1861. Turritella vertebroides Gabb, Synop. Moll. Cret. Form., 



p. 148 (92). 

 1864. Twrritella vertebroides Meek, Check List Inv. Foss. N. 



A., Cret. and Jur., p. 19. 

 1868. Turritella vertebroides Con., Cook's Geol. N. J., p. 729. 

 1892. Turritella vertebroides Whitf., Pal. N. J., vol. 2 (Monog. 



U. S. G. S., vol. 18), p. 146, pi. 18, figs. 13-18. 

 1905. Turritella vertebroides Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), p. 21. 



Description.- — Shell acutely angular, the apical angle about 20" ; 

 the dimensions of a large individual from Alabama are: maxi- 

 mum diameter, 20 mm. ; length with the apex broken, 64 mm. ; 

 number of volutions preserved, 10. Suture moderately impressed, 

 situated a little below the center of a rounded, revolving furrow ; 

 surface of the volutions depressed convex from suture to suture. 

 Surface marked by four or five subequal, angular, revolving 

 costse, with several much finer ones occupying each of the inter- 

 spaces, and by fine transverse lines of growth which describe a 

 concave curve in passing downward from the suture. In the 

 casts the volutions are moderately close, the surface is smooth 



