156 



Keport of the State Geologist. 



PLATE VII. 



Probeloceras Lutheri, Clarke. 



Figure 1 . The primary whorls enlarged ; showing the crests upon the venter 

 produced by the concentric varices, x 10. 



Figure 2. A shell of two and one-half volutions, broken back to the first 

 septum and showing the length of the body chamber. The ventral 

 ridge is already developed and the crests upon its surface are not 

 resorbed by overlap, x 20. 



Figure 3. An older shell, enlarged to the same degree ; showing the promi- 

 nence of the varical crests in their hyponomic recurvatures. x 20. 



Figures -4 and 5. Much older shells, of four to four and one-half volutions. 



They show the character of the suture in this early ephebic condition 

 and the well developed ventral ridge, but they have lost all trace of 

 superficial ornament, x 3. 



The foregoing specimens are barite replacements from the 

 calcareous nodules, Honeoye lake. 



Figure 6. A small shell showing an early form of the suture, x 3. 

 Naples beds, Naples. 



Figure 7. A mature specimen, natural size. Naples. 



Figure 8. The type specimen of Goniatites Luther i, Clarke, Naples. 



Figures 9 and 10. Two shells from the shales at Naples, showing the usual 

 aspect of the species, and the latter (fig. 10) exhibiting a fine 

 striation on the final whorl. 



Beloceras iynx, sp. nov. 



Figures 11, 12 and 15. Specimens, natural size, showing the mature form of 

 the suture. 



Figure 13. A young, pyritized shell, showing immature phases of the suture 

 and a fine surface striation. x 3. 



Figure 14. Enlargement of a part of another young shell, x 3. 



Figure 16. A part of a mature shell which presents the fully developed 

 condition of the suture, x 2. 



These specimens are all from the shales at Naples. 



