192 Corresponde7ice — A. Heard. 



Professor Kendall's map, though it purports to be copied 

 from those of the Geological Survey, exaggerates the moraine-like 

 character of the two bands of sand and gravel by omission of the 

 significant outcrop east of Naburn. 



He complains of my having stated the height of the village of 

 Stillingfleet, which was inserted to show that the sands and gravels 

 there occur only 10 feet above the level of the Ouse and at the 

 same height as the sands at Deighton Grove. Why should 

 Professor Kendall transfer the height of Stillingfleet to the ridge near 

 that village ? 



Professor Kendall does not reassert his view that the band from 

 Fulford to Escrick is an esker. It is, of course, true that the lower 

 part is covered by the Warp Clay so thf t it is invisible ; but the 

 osar structure should be recognizable in the exposed part in which 

 there are good sections in a series of gravel pits. There is nothing 

 in Professor Kendall's restatement of his views either to show that 

 the Fulford-Escrick band of gravel is an osar or to overcome 

 Professor Bonney's weighty objections to the view that the two 

 crescentic ridges of drifts should be regarded as moraines, although 

 Professor Kendall may regard acceptance of that identification as his 

 shibboleth in glacial geology. 



My paper was written in the hope that by summarizing the 

 distribution of English esker formations (in accordance mainly with 

 visits made to them during the past twenty-five years), and by calling 

 attention to their apparent absence from many parts of the country, 

 other examples would be recognized and recorded. In the 

 classification on p. 42 of my paper I have included, with one 

 exception, only kames which I have personally examined ; the two 

 osars are accepted on the evidence of Professor Boulton's paper and 

 on information kindly supplied me by Mr. Dixon, which seemed 

 conclusive. I hope that investigations similar to theirs will fill in 

 some of the gaps on what appears to be the remains of a long series 

 of kames with occasional osar along the line where the glaciers 

 •ended on the English lowlands. 



J. W. Gregory. 



THE PETROLOGY OF THE PENNANT SERIES. 

 Sir, — Mr. E. Dixon, of H.M. Geological Survey, has kindly 

 called my attention to an error in my paper in the February number 

 of the Magazine. On p. 91, the statement " areas of. Lower Coal 

 Measure age were undergoing denudation " should, of course, read 

 ",areas similar to those of the Lower Coal Series, were undergoing 

 -denudation ", as there is no evidence of the presence of Lower Coal 

 Measures in South Wales. 



A. Heard. 

 Department of Geology, University College, 

 Newport Eoad, Cardiff. 

 20th March, 1922. 



