EXPLANATION OF PLATE XVIL 



43. Belemnites Voltzii, n. s. (Upper Lias, Whitby.) 



/. Lateral view of a symmetrical specimen. 



d. Dorsal aspect of the same. 



V. Ventral aspect of the same. 



I" . Lateral view of a larger specimen. 



^ . Phragmocone, seen laterally. 



The same, seen dorsally, 



s . Transverse section at the alveolar apex. 

 6-". „ „ near the apex of the guard. 



44. Belemnites ventralis, n. s. (Upper Lias, Robin Hood's Bay.) 



/. Lateral view ; the apex worn. 



d. Dorsal view of the same. 



V. Ventral aspect of the same. 



The striation is seen on each. 



5-'. Transverse section at the alveolar apex. 

 6f". „ „ further along the guard. 



s" . „ „ near the apex of the guard. 



45. Younger examples, with unworn apices. The points are striated. (Upper Lias, 



Wliitby.) 



/. Lateral view. 



v. Ventral view, to show the rather long groove. 



v". Another specimen, in which only the faintest trace of such a groove appears. 

 These three figures are not very easily distinguished from the young of 

 Belemnites vulgaris. 



