Percy F. Kendall — Glacial Geology. 495 



the Liassic Gault and Chalk fossils recorded from Gloppa Mr. 

 Nicholson found one Liassic fossil himself, while the remainder 

 were obtained from the workmen. 



We are told that Mr. Nicholson "has no reason to donbt their 

 genuineness." I fancy there are very few geologists who will share 

 this confidence in the accuracy of the British navvy. The gangs 

 are recruited from all parts of the country, they have a great aptitude 

 for turning a penny, and the way they carry specimens from one 

 job to another is matter of notoriety ; but, by way of illustration, 

 I will mention two out of many cases within my own experience. 

 At Moel Tryfaen I was offered a West Indian Pyrula, and several 

 other obviously recent shells, by a workman, who protested that he 

 had found them in the famous Drift deposits ; and in the cutting of 

 the Levenshulme railway, when I asked an intelligent ganger if he 

 had found any shells in the Boulder-clay, he produced from his 

 pocket two well-preserved specimens, Fusus bulbiformis and Turritella 

 sulcifera I Need I say that I should want better evidence before I 

 could admit the occurrence of the Gault Iiioceramus concentricus in 

 the Gloppa gravels. It is not surprising that Mr. Nicholson, in his 

 maiden etfort, of which he has such good cause to be proud, should 

 manifest a willingness to accept the testimony of the navvy, but in 

 a geologist of Mr. Eeade's experience such credulity is wonderful. 

 Let me ask Mr. Reade how he would get Gault fossils (from the 

 condition of the specimen I should say it came from the Cambridge 

 Greensand) round and up to Gloppa by the agency of floating ice ? 

 The twists and doubles would need to be of a very complicated 

 description, and when they were all performed a vertical rise of 

 close upon 1000 feet would have to be effected. 



The "exceptions" have now nearly reached the irreducible mini- 

 mum by this process of elimination, but I must whittle them down 

 a little farther. The coal at Corwen found by Mr. Mackintosh 

 must be accepted by all who know anything of the work of that 

 m,ost conscientious and painstaking observer. But, though I un- 

 reservedly accept the fact, I must demur to the inference that the 

 coal came from Ruabon. Up the Vale of Llangollen, though I have 

 found a round dozen of moraines of a glacier which came down the 

 Vale, neither I, nor, so far as I can learn from his writings, Mr. 

 Mackintosh ever found the slightest trace of any movement or of 

 any transport up the Vale from Ruabon in the direction of Corwen. 

 I am writing away from my books and papers, and therefore do 

 not speak positively npon the point, but I have some recollection 

 of seeing plant-remains in the state of coal which were found by 

 Dr. Hicks in the slates at Corwen. If this be the case it would suggest 

 a much more probable origin for the coaly fragments than Ruabon. 



The occurrence of Waldheimia ohovata at Wellington is avouched 

 by Dr. Callaway, and therefore is inexpugnable ; by the ice-sheet 

 theory, however, there is still an explanation without calling in 

 the aid of a capping of Oolite in the Liassic basin of Market Drayton. 

 The central cross valley of England through which the Trent runs 

 was the site, according to Lewis, of a large extra-morainic lake, 



