]Vilmore : The Limestone Knolls of Craven. 331 



forms of the g'enus Oppelia, the whole of the intervening' deposits 

 being" apparently devoid of these fossils. 



In the beds with Beleninites ewaldi, which may prove to be 

 a distinct zone between the brnnsviceiisis and niininins zones, 

 no ammonites have as yet been detected, but in the minimus 

 zone H. interniptiis, Brug-., has been found. 



The Criocerata have been found to exist in most, if not all, 

 the deposits from the uppermost part of the Belemnites lateralis 

 zone to the top of the Belemnites brtinsvicensis zone, and are 

 especially numerous about the middle of the Beleninites jaculum 

 zone. They are, however, difficult to determine, being- both 

 frag-mentary and ill-preserved. 



The following is a list of the specimens obtained : — 

 *Crioceras d imal i d'Orh C mid. to Crioceras fissicostatum ? Room. B 



THE LIMESTONE KNOLLS OF CRAVEN, f 



A. WILMORE. 



The Craven Lowlands district, between the g-reat faults on the 

 north-east and the grit hills of the Pendle Range on the south, 

 is characterised by a well-known series of limestone knolls 

 which have been the subject of much discussion. Having 

 worked in the district for some years, I venture to make the 

 following suggestions : — • 



The words ' knoll ' and ' reef-knoll ' seem to be differently 

 understood by different workers. It seems to me desirable to 

 drop the term 'reef-knoll.' This term was applied by Mr. 

 Tiddeman to certain extreme members of a series : there is 

 every possible gradation between these and ordinary rounded 

 knolls to which the term would never be applied. Further, the 

 hills so named by Mr. Tiddeman have not all originated in the 

 same way. 



* Determined b\' Dr. A. von. Koenen. 



t A paper read to Section C of the Meeting ol" the British Association, 

 York. 



igo6 September i. 



