﻿Vol. 66.'] LIMESTONE SOUTH OF THE CRAVEN FAULT. 551 



List of Fossils obtained. 



Michelinia cf. tenitisepta (Phill.). 



Spirifer bisulcatus, Sow. 

 Spirifer trigonalis (Mart.). 

 Martinia glabra (Mart.). 

 Productus pustulosus, Phill. 

 Productus semireticulatus, Mart. 

 Productus martini, Sow. 

 Productus giganteus, Mart. f 

 Bhipidometta michelini (L'Eveille). 



Cyaihaxonia rushiana, Vaugban. 



Lophophyllum costatum (M'Coy). 



Zaphrentis, sp. nov. 



Zaphrentis amplexoides, sp. nov. 



Zaphrentis costata, M'Coy. 



Zaphrentis ambigua, R. Gr. Carruthers. 



Zaphrentis omaliusi, M.-E. & H. 



Caninia sp. 



Clisiophyllum sp. 



Diphyphyllum sp. 



Syringopora cf. ramulosa, Goldf. 



(Eare.) 



Also some gasteropods and cephalopods which haye not been determined. 



The shales and some of the limestones are very rich in corals. 

 In the face of one block of stone, rather less than 2 feet in area, 

 I counted over 120 individuals of Cyathacconia, Lophophyllum, 

 Zaphrentis, and Caninia. It is obvious that among such a wealth 

 of material there is considerable work for the future. I may point 

 out here that there is some similarity between the general faunal 

 assemblage of these beds and that of Crag Laithe Quarry. 



(3) The Knoll Region of Cracoe, Thorpe, and Linton. 



Much has been written concerning this famous region, famous 

 ^ilike for its peculiar topography and for the beauty of its fossils. 

 There has been a long controversy concerning the origin of the 

 prominent knolls of limestone which are found in the district. 

 It is not necessary to repeat the theories of Mr. Tiddeman and of 

 Dr. Marr, because these are now well known and have been so 

 often summarized. 1 propose, however, to submit some remarks on 

 those theories, and to offer a contribution towards the solution of 

 the difficulties (in my opinion more apparent than real) which have 

 brought these knolls into greater prominence in geological literature. 

 My remarks will best follow a detailed account of some observations 

 made in the district during the past few years. 



I propose to describe some of the exposures in the separate knolls, 

 more especially those of Elbolton and Swinden, the latter being 

 now dissected by quarrying operations and presenting a fine oppor- 

 tunity for the study of the internal structure of a knoll. 



A series of these knolls may be seen along a line which is roughly 

 parallel to the grit fells of Cracoe and Thorpe. In order from east 

 to west they are Keal Hill, Elbolton, Stebden, Butterhaw, Carden, 

 and Skelterton. Stebden stands back from the rest, nearer to the 

 grit fells. Carden is only a small knoll, but ought to be included 

 in the series. It forms a small dissected mass of limestone, sepa- 

 rated from Butterhaw and Skelterton on either side by small 

 streams, which coming down from the grit moors so close at hand, 

 have tremendous erosive power. 



Elbolton Knoll. — This is the largest of the knolls, and forms 

 a fine hill west of the hamlet of Thorpe. The hill has been explored 



