THE CEPHALOPODA 



'85 



arms 



FIG. 53. BELEMNITES. 



a, Restoration of the living Belemnite (modified from d'Orbignyf). 

 F, Funnel; G, guard; Pro., pro-ostracum. b, b' t Restoration o 

 phragmocone, in front view and section (after Crick). P, Protoconch; 

 Phr. , phragmocone; S, siphuncle. f, Atractites philippii H)att and 

 Smith, Carnic, California. Guard (G) partly broken open showing 

 phragmocone (Phr.}. (After Hyatt and Smith.) d, B.ekmnofsis 

 bessimis (d'Orbigny), Bathonian. e, Hibolites hastatus (Blainville), 

 Callovian (Oxford Clay). /, Hastites clavatus (Blainville), Char- 

 mouthian. g, Oxyteuthis acutus (Miller), Sinemurian. h, Coslo- 

 teuthis excavalus (Phillips), Sinemurian. d-h, Ventral views: dotted 

 lines indicate the alveolus, unbroken lines the grooves on the surface. 

 d'-h', Cross-sections, the dot marking the axis, d. After d'Orbigny ; 

 e-A, after Phillips. (All X J, except a). 



