Correspondence — A. R. Hunt. 431 



the Bovey Beds to the Bournemouth horizon as Eocene. My reason 

 in writing on the subject is that Pengelly's Hempstead flora seems 

 to have been overlooked. Indeed, in a recent text-book I cannot 

 find either Hempstead or its beds, unless Hempstead has turned into 

 Hamstead.^ As the collection seems to have been specially made for 

 Mr. Pengelly, and he recorded it in a paper of four pages in provincial 

 transactions, its burial may have been too effective. 



With regard to sands suspected to be of Dartmoor origin, the 

 question can be readily settled by the character of the inclusions in 

 the quartz. With respect to the Bovey clays, the presence of the kaolin 

 at Bovey is exactly matched by its absence from its place on 

 Dartmoor, where there is much evidence of the dissolution and 

 removal of the felspar. This might be looked for with a semi- 

 tropical vegetation and much consequent carbonic acid. 



Eeferring to the Rev. Osmund Fisher's interesting note about the 

 pink felspar crystals, which he suggests may have been derived 

 from the English Channel area, he might be interested to examine the 

 collection of rocks from the English Channel which were graciously 

 accepted by the Woodwardian Professor, now many years ago. There 

 was no evidence in the Channel of rocks likely to decompose and 

 liberate pink felspar crystals. No. 2, with "lai'ge pale flesh- 

 coloured orthoclase twins," is a hard rock. There is an abundance 

 of red felspars on Dartmoor, ranging from a dark brick red ; but 

 these run in shades of red rather than pink, and are, so far as I am 

 aware, not orthoclase. Moreover, if associated with quartz, they 

 could be authoritatively distinguished from the Channel felspars, so 

 far as those are known. 



I feel an apology is due for my thus trespassing on your space on 

 a subject which, except indirectly, is foreign to my own lines of 

 inquiry. Of the Eocene and Miocene floras I am profoundly 

 ignorant, but the discrimination of sands derived from the Channel 

 and from Dartmoor is a simple matter in many cases. If sands 

 oontain chlorides we may be sure they were not derived from rocks 

 known in the Channel ; whereas if chlorides are entirely absent we 

 may be equally sure they do not hail from Dartmoor. 



The problem of the flora is as follows : — According to Pengelly 

 and Keeping the Bovey Beds are equal to the Hempstead Beds, and 

 are Tongrian. According to Mr. Starkie Gardner the Bovey Beds 

 are equal to the Bournemouth Beds, and are Lutetian. Hence, 

 according to Euclid, Tongrian must be equal to Lutetian, or 

 Oligocene =: Eocene, " which is absurd." The most obvious solution 

 is that Euclid is a discredited text-book, and that things which are 

 equal to the same things are not equal to one another. A plausible 

 explanation would, however, assume that Pengelly misnamed his 

 Hempstead fossil plants ; but it is clear they were described by some 

 expert specialist, as new species were detected. A. R. Hunt. 



Jicly Wth, 1905. 



^ [The original name for the locality in the Isle of Wight is Hamstead, -which was 

 changed by the Survey into Hempstead. — Edit. Geol. Mag.] 



