I. Introduction. South of the great Craven Fault is a district which may well be termed the Craven Lowlands. It lies between the limestone sears of Settle, Malham, and Grassington on the north and the grit hills of the Pendle Range on the south. The district thus defined may be held to include all that part of Craven which extends from Clitheroe to Skyreholme, and from the so-called 'middle branch' of the great fault-system, to the grit hills of Simon's Seat, Burnsall Fell, Flasby Fell, Carleton Moor, and westwards to Pendle. The Carboniferous Limestone and Pendleside Beds, which occupy almost the whole of the district under consideration, are everywhere very much folded and faulted. The greater part of the region is much obscured by drift. With the exception of a good section at Troller's Gill (which does not, however, show any considerable thickness of beds) there are no long continuous sections, and the geologist must remain perforce content with the numerous isolated exposures which are scattered over the whole district. Owing to the contiuually changing dips, it is not easy to make out the sequence of the beds. This paper will be confined to a description of the Carboniferous Limestone, as it may be seen in the various exposures between Swinden Moor on the west and Skyreholme on the east. I have previously discussed other parts of the Craven Lowlands. The lithologieal character of the limestone varies considerably in different parts of the district, the most widely different types being the greyish-white, irregularly-bedded shelly limestone of Elbolton