JET. 48.] BOULDER CLAY OF WALES. 153 



into Cefn Cave, and, by its superposition to the deposits con- 

 taining mammalian remains, testifies, like the buried forest, to 

 the presence of a subaerial surface immediately before the 

 transport of northern blocks." 



Now is this correct ? You have examined the deposits and 

 found the Boulder Clay near Bryn Elwy. 



Does the Boulder Clay penetrate into Cefn and overlie the 

 mammalian deposits ? If so, it is a fatal blow to your position 

 in Gower. 



Do look into the matter and let me have a line in reply. 

 Yours very sincerely, H. FALCONER. 



J. Prestwick to If. Falconer. [Undated.] 



MY DEAR FALCONER, I have this morning received your note, 

 and am sorry I missed you in town. I do not feel in the 

 slightest degree uneasy about the difficulties raised by Austen 

 and Sir Charles. Trimmer is mistaken altogether about Cefn 

 Cave. 1 There is plenty of Boulder Clay about the district, but 

 not a bit in the cave. Sand and shells, like your caves, do, 

 however, occur there. I have a note from Mr Homer about 

 extending my note and making a short paper of it, and suggesting 

 a title. The former I accept the latter will not do. I must see 

 more about the Boulder Clay of Gower before I can venture to 

 say much about it. The raised beach I feel pretty certain 

 about. Still we want the level of the beach at the Mumbles, its 

 position, &c. I shall if possible run over there for a day or two 

 before I return to town. I am now en route for Exeter and 

 Plymouth. If you have any suggestion to give me, please drop 

 me [a line] either [on] your return to Barnstaple, or else on 

 Thursday to the P.O., Swansea. Yours ever truly, 



JOSEPH PRESTWICH. 



A few extracts from one of the 1860 note -books 

 mention June 1 as the date of a journey to Newbury, 



1 More recent observations on the caves in the Vale of Clwyd seem to 

 show that certain of the cave- deposits with Pleistocene mammalia are 

 older than the Boulder Clay of the district. See Dr H. Hicks, Quart. 

 Journ. Geol. Soc., vol. xliv. p. 561, and vol. liv. p. 91. 



