Clarke — The Naples Fauna. 155 



Manticoceras apprematttm, sp. nov. 



Figure 27. The inner whorls enlarged to show the character of their orna- 

 ment, x 3. 



Naples beds, Griswold's. 



Figures 28 and 29. Ephebic shells from the Styliola limestone, Middlesex 



Manticoceras Pattersoni, var. sttliophilum. 



Figure 30. Adult shell, showing the fine striation of the final whorl. 

 Naples beds, Naples. 



Manticoceras tardum, sp. nov. 



(See Plate I.) 



Figure 31. A shell of four volutions, showing the very wide umbilicus and 

 the simplicity of the ornament, x 3. 

 Naples beds, Naples. 



