PLATE LXVIII. 



CONOCARUIUM CUNEUS, Var. TKIGONALE. 

 Page HO. 

 See Plates 67, 94. 

 "Pig. 1. The ventral side of a small siwcimen. 

 Figs. 4-0. Ventral and cardinal views and right side of a small specimen retaining the shell. 



Comiferous limestone. Near Zjouisville, Ky. 

 Fig. 7. An enlargement of the sui-face from the post-cardinal slope of the pi-eceding. 

 Fig. 8. An enlargement showing a portion of three radii and the extension of the shell beyond the 



umbonal ridge, from the sjwcimen fig. 6. 

 Fig. 9. Cardinal view of a specimen .showing the surface nwirkiiigs. 



Cornifei-ous limestone. Fallx of the, Ohio river. 

 Figs. 10, 11. Left side! and cai-dinal views of a specimen retaining portions of the test. 



Comiferous limestone. Near Loulte'dle, Ky. 

 Fig. 12. Ventral view of a specimen showing the pedal opening and denticulate<i margins. 

 Fig. 13. Cardinal view of a ca.-st of the interior, showuig anterior and posterior muscular scars. 



Coraiferoiis limestone. Columlnis, Ohio. 

 Fig. 14. The right side of a spec'inien, preserving portions of the test and showing the extent of the 



umbonal expansion of the shell. 

 Fig. 16. Posterior view of the specimen fig. 12. 

 • 



CONOCAKDIUM OhIOENSE. 



Vug 4U. 

 Fig. 2. The left side of a six'cimen. 



Comiferous limestone. Near Louixmlle, Ky. 

 Fig. 3. The left side of a nearly entire individual, enlarged to two diameters. 



Comiferous limestone. Fhlla of the Ohio river. 



^f|M^ CONOCABUIUM NOKMALE. 



^ I'agc 411. 



Figs. 17, IH. The rigli; ; I'ardinal views of a lai-ge partial cast of the exterior of a specimen. 



Hamilton group. Ciimlxrland, ild. 

 Fiir 1!' The right sifle of a caiit of a sm.'illi'r specimen, showing the anterior muscular scar and the tilling 

 of the foot sheath. 



Hamilton group, (iimberland, Md. 



CONOCARDIUM EbORACEUM. 



Page 11-2. 

 Figs. 20, 21. Ventral and cai-dinal views of a compressed specimen. 

 Hamilton group. York, Livingston Co., N. T. 

 Figs. 22, 23. Ventral view and left side of a small specimen retaining the test and surface ornamentation, 

 enlarged to two diameters. 



Hamilton group. Tork, N. ¥. 



