MOLLUSCA. 699 



sharply carinate at about their mid-height, the space between the 

 carinae of adjacent volutions being a broad, deep, concave, re- 

 volving depression, whose upper slope is more abrupt than the 

 lower, and whose greatest depth is a little above the middle. 

 Suture situated near the middle of the revolving depression, 

 a little below the line of greatest depth. The entire surface of the 

 shell is marked with very fine, elevated, revolving lines. 



Formation and locality. — This species differs from all other 

 New Jersey Cretaceous species of the genus, which have been 

 observed, in the strongly carinated volutions, the shell being in 

 this respect a miniature example of T. mortoni var. postmortoni 

 Harris, from the Eocene.^ The species here described, however, 

 is quite distinct from that Eocene form in other respects. The 

 type specimen is the apical portion of a shell only, being incom- 

 plete at the opposite extremity, so that it may be found to grow 

 much larger with a greater number of volutions. 



Pormation and locality. — Merchantville clay-marl, L,enola 

 (163); Woodbury clay, near Haddonfield (183). 



Geographic distribution. — New Jersey. 



Turritella trilira Conrad. 

 Plate LXXIX., Fig. 4-S. 



i860. Turritella trilira Con., Jour. Acad. Nat. Sci. Phil., 2d 



ser., vol. 4, p. 285. 

 1861. Turritella Corsicana Shum., Proc. Bost. Soc. Nat. Hist., 



vol. 8, p. 196. 

 1861. Turritella trilira Gabb, Synop. Moll. Cret. Form., p. 147 



(90- 

 1864. Tmritella corsicana Meek, Check List Inv. Foss. N. A., 



Cret and Jur., p. 18. 

 1864. Turritella trilira Meek, Check List Inv. Foss. N. A., Cret. 



and Jur., p. 19. 

 1902. Turritella trilineata Hill and Vaughan, U. S. G. S., Geol. 



Atlas, Austin Folio, fig. 47. 



'Eocene Rep., Md. Geol. Surv., pi. 26, fig. $. 



