PKESTWICH CRAG-BEDS OF StTPFOLK AISTD NORFOIK. 453 



Wood, jun. *, Mr. J. E. Taylor f, Mr. Harmer J, and Mr. Maw §, the 

 Eev. 0, Fisher ||, Mr. Ray Laukester ^, and others, have since con- 

 tributed largely to onr knowledge of it. With respect to these papers, 

 many of which (those especially of Mr. Wood and his colleagues) 

 are marked by much research and original opinions, I feel rather 

 at a loss how to proceed. Were I to give the views of each 

 author and discuss the points of difference between us, I fear I 

 should have to lengthen this paper to an extent which might be 

 wearisome to the Society. If I do not therefore always notice all 

 the points wherein I may agree or differ from other observers, I 

 beg they will not consider it arises from oversight, or from want of 

 due estimation of their researches, but from the mere necessity of 

 avoiding the long details which a discussion of the controverted points 

 would entail. I may be further justified in this course by the cir- 

 cumstance that my own researches are in great part anterior to 

 most of the papers in question. It may be observed that where 

 the several conclusions arrived at thus independently prove to be 

 concordant, they must be entitled to greater weight. One object of 

 this paper is also to give more fully than has been hitherto done 

 the stratigraphical details of the several pits and particular coast- 

 sections in which the relation of the several beds can be determined, 

 following their range from the Red-Crag district and proceeding 

 northwards through the Norwich-Crag district. 



I described the ChiUesford beds in 1849 ; and I then expressed 

 an opinion that they were probably of the age of the Mammali- 

 ferous Crag of Norfolk, or possibly one degree more recent, an 

 opiuion shared by Mr. Searles Wood after an examination of the 

 fossils **. My own observations, continued since that period, and 

 the active researches of many of the geologists just named, have 

 confirmed that suggestion. It has further been shown that the 

 Norwich Crag may be divided into an upper and lower division, 

 the former corresponding with the Chillesford Sands and possessing 

 a deeper-water fauna of a more northern character than the other,-— 

 conclusions which I accept with, possibly, a few modifications. 

 Another interesting question raised by Mr. S. Wood, jun., and his 

 colleagues relates to the position of the Weybourne Crag 5 and on 

 this we do not altogether agree. 



In my last paper it was shown : — that the Chillesford Clay was 

 probably the upper and deeper-sea portion of the second or higher 



* " On the Eed and Fhivio-marine Crags " &c., Ann. & Mag. Nat. Hist. March 

 1864 ; ' On the Upper Tertiaries of the Eastern Counties,' 1865 ; Greol. Mag. 

 vol. T. p. 452 ; Quart. Jooi'n. Greol. Soc. vol. sxii. p. 546. 



t Geol. Mag. vol. iii. p. 273, vol. iv. p. 331, and vol. vi. p. 231. 



+ Ibid. vol. vi. p. 231. § Ibid. vol. iv. p. 560. 



II "On the Eelation of the Norwich Crag to the Cliillesford Clay," Quart, 

 Journ. Geol. Soc. vol. xxii. p. 19. 



^ Quart. Journ. Geol. Soc. vol. xxi. p. 221 ; and Geol. Mag. vol. iv. p. 91. 

 vol. V. p. 254, and vol. vi. p. 47. 



** Instead, however, of their overlying both the Eed and Coralline Crag un- 

 eonformably, I afterwards found that, while they were imeonformahle to tht,-, 

 latter, they succeeded to and passed transgressively off the former. 



