Correspondence—Mr. W. Gresley—Mr. D. Mackintosh. 191 
Turritella terebra, and Astarte multicostata? as found at Bovevagh. 
The former is the characteristic shell at that place, and the only one 
at all plentiful. Some time since, I had the opportunity in company 
with two other geologists of examining the river-bank near the old 
church at Bovevagh, and we found a number of specimens of Turri- 
ella, but not in such abundance as we had been led to expect. ‘The 
only other fossil we could find was one valve of Venus gallina. 
The inaccuracies cited would no doubt have been avoided by relying 
more on the work of Portlock, and subsequent writers having a per- 
sonal knowledge of the country and its geology, and less on that of 
a gentleman, who, however qualified in other respects, has not, I 
fear, had the advantage of personally examining the beds concerning 
which he wrote, and who has consequently not been in all cases as 
accurate as could be desired when treating of the drift of the North 
of Ireland. Mr. Howorth’s argument is scarcely affected by the 
above corrections, but the slightest error should be avoided in such 
discussions. Wituram Swanston, F.G.S. 
Brurast, 5¢h March, 1883. 
HAMATITE IN THE PERMIAN BRECCIAS. 
Srr,—Can any of your readers inform me of any locality or locali- 
ties where Hematite occurs in situ in the neighbourhood of the Long- 
mynd or of other parts in the West of England or in Wales, whence 
these Breccias of Central England are considered to have been 
derived? Also, are the Hematites fossiliferous, and have they been 
commented upon or in any way referred to by geologists? If so, in 
what publications do they appear ? W. 8S. GRESLEY. 
OvERSEAL, ASHBY-DE-LA-ZOUCH. 
RECENCY OF THE CLOSE OF THE GLACIAL PERIOD. 
Sir,—As very little attention has been devoted to this subject in 
England, you would oblige by inserting extracts from a letter I 
received from the late Mr. Belt’ a few years ago. ‘I am heartily 
with you about the comparative recentness of the Glacial Period. 
My earliest lessons in glaciation were in the north of England, where 
the freshness of the ice-tracks are most remarkable. All the argu- 
ments for putting it back are founded on theories which may be, 
and | think are, incorrect. ... I shewed some time ago that the 
argument that had been founded on the cutting out of the gorge 
below the falls of Niagara, was a weak one, as only three miles, and 
that in the softer rocks, had been excavated since glacial times. 
Some of the American geologists, including Professor Hall, have 
visited Niagara since, and convinced themselves that my explanation 
is the right one.” 
Dr. J. W. Dawson, in his review of Wallace’s “‘ Continental and 
Island Life,” ? remarks that “(in Canada the character of the river- 
courses cut through the Glacial beds, and their very unformed and 
1 See an account of Mr. Belt’s theory of the Glacial Period, with accompanying 
remarks, in the Presidential Address to the Geologists’ Association (1874), by Henry 
Woodward, F.R.S., F.G.S. 2 Princetown Review for July, 1881. 
