J. F. BLAKE ON THE EIMMERIDGE CLAY OE ENGLAND. 203 



the latter having been procured by Mr. Keeping for the Cambridge 

 Museum. 



In the cuttings of the Louth and Lincoln Railway we get again 

 the succession of some of the beds. The actual junction with the 

 Neocomian I did not see, as it was covered by drift. In the next 

 cutting to the west we have the following section : — 



Thin limestone band, 4 in. 

 Blue shale, 9 ft. 



Hard band of hydraulic limestone, 8 in., with Ammonites pectinatus (Ph.), 

 Lucina minuscula, Ostrea gihbosa, and Discina latissima. 

 Light blue dicey clay, with shale full of Lucina minuscula. 



The same papery shales with numerous fossils (Amm. biplecc, 

 Cardium striatulum, &c.) occur in the next two cuttings; and pro- 

 bably intermediate to them are the soft blue, not very fossili- 

 ferous, clays of a brick-yard by the railway-side, with Amm. biplecc, 

 Lucina minuscula, and Ostrea gibbosa ; in this case, where we have 

 the most complete section, we are struck with the general resem- 

 blance of the series to that at Kimmeridge ; and this is the more 

 noticeable, because the next good exposure, that at Nettleton Hill, 

 shows us clays above the paper-shales, which are less and, indeed, 

 scarcely fossiliferous, perhaps 30 ft. in thickness. The paper-shales 

 here, i. e. at Acre House, are very fossiliferous, and yield Discina 

 latissima, JBelemnoteuthis, Ammonites pectinatus, Avicula vellicata, 

 and Homomya gracilis (?). The series here, however, though pos- 

 sibly complete, cannot be so thick as in the south, as the Lower 

 Kimmeridge is met with at the base of the hill at Holton-Moor 

 station, and the dip is certainly not great. 



I have not traced these beds further north ; but Mr. Judd records 

 their recurrence, after having been covered by the Chalk, in Filey 

 Bay, where they contain the same fossils, together with Lingula 

 ovalis in abundance, which, in spite of Dr. Waagen's quoting it as 

 characteristic, I have everywhere else found to be a rare fossil in the 

 Upper Kimmeridge, and to characterize rather the lower portions. 



Everywhere then, as already remarked by Mr. Judd, the upper- 

 most portion is thinly stratified and slaty. The contained suite of 

 fossils have quite a facies of their own. We remark the commonnes s 

 of Aptychi and Teuthiform Cephalopods. Discina latissima seems 

 absolutely characteristic, although Prof. Phillips records a fossil by 

 that name from the Oxford Clay. Astarte lineata, and Avicula 

 vellicata, though rarer, also seem peculiar. Lucina minuscula is the 

 bivalve that seems hitherto to have escaped description, and which 

 crowds every surface ; and though it is also met with far more 

 rarely in the lower beds, by its abundance here it becomes really 

 characte: istic. The Cardium striatulum is the C. lotliaringicum of 

 Waagen's list, and, though more abundant in the upper beds, is scarcely 

 characteristic, unless indeed we ought to divide the species. The 

 remaining fossils are either rare or are also met with in lower beds ; 

 but their number is few. Of the whole list of Mollusca, containing 

 21 certain species, 14 are peculiar, and 7 are common to lower or 

 higher beds — one, Ammonites pectinatus (Ph.), occurring also in the 



