154 Sherhoru : On flic Bclcviiiites of flw Chalk of Yorkshire. 



C I. — From the base ot the Micrtis/cr ror-aiii^nd/m/n-xoue, 



Hii^h Stacks. 

 C. 2. — From the Micraster cor-angiiitmni-zow^., between High 



Stacks and South Sea Landing". 

 C. 3. — From the upper part of the Micraster cor-uugiiinnni-Aow^^ 



west of South Sea Landing". 

 U. — From Uiiitacrin iis-hund, between South Sea Landing and 



Danes' Dike. 

 M. — ^From J/a fs?tpi/cs-ha.nd, west of Danes' Dike. 

 Q. I. — From quadratus-zow^, Sewerby Cliff. 



C.I. 



C.2. 



C.3. 



u. 



RT 



M. 



Q... 



r7\ 



E.H. 



Bessiiii^hv 



Bessingby 

 W. 



r7\ 



Burton 



m 



Huston 



Parva. Q- 



r~^ 



r\ 



r\ 



\ u / 



Drawings of Alveolar-Ends of Actinocamax granutatus, showing- Progressive 

 Deepening of the Alveolar Cavity as the Belemnite ascends in the Zones. 



(Measurements in uiilliinetres.) 



(By permission 0/ Dr. Roiue and the Council of the Geologists' Assoiiatioii.] 



Q. 2. — From (/iiadra/as-zone, Sewerby Cliff. 



Q. 3. — From (/nadra/i/s-zone, Sewerby Cliff. 



Bessing"by E. — ^From guadra/us-zone, East Bessing'by. 



Bessingby W. — From (/iiadra ins-zone, West Bessingby. 



Burton Agnes. From (/aadraius-zone at Burton .Agnes. 



Ruston Parva. -From (/aadraias-y.one at Ruston Parva. 



Q. X. — Typical example of Aciiiiocamax qnadratus from the 

 qtiadrai US-zone of Haniliam, Salisbury. This specimen 

 shows the deep alveolus of the true quadraius form, 

 and the cross-section of that cavity is of the typical 

 quadrangular shape. 



Naturalist, 



