EXPLANATION OF PLATE VL 



Fig. 



15. Belemnites paxtllosus. 



/. Lateral view, 



V. Ventral aspect, ) of specimen with eroded and striated apex. 



d. Dorsal aspect, 



s. Longitudinal natural section of the guard, with a portion of the phragmo- 



cone not in section. Natural sections are frequent in this species. 



s'. Longitudinal section of a younger individual. 



s" . Transverse section of the guard at the ape.x of the alveolus. 



s". Transverse section of the guard near the end. 



<p. Phragmocone, seen laterally. 



16. Belemnites apicicurvatus. 



/. Lateral view, showing the short groove near the point. 



V Ventral aspect. 



d. Dorsal aspect, 



s. Longitudinal section. 



s. Section across the alveolar region. 

 ,v"', 4-'', 5'. Sections nearer and nearer to the end. 



^. Side view of the phragmocone, always more arched than in B. paxillosus. 



a. Striae magnified. 



