140 Correspondence—Dr. A. Irving —Mr. Alfred Harker. 
constant introduction, by so distinguished a petrologist, of person- 
alities, which are quite unworthy of a man of science, which are 
sure to revert upon himself, and which may even reflect indirectly 
on the British School of Petrology, of which for so many years 
Professor Bonney has been a prominent exponent. 
Souruwoop, Torauay, 18th February, 1898. A. R. Hunt. 
SCANDINAVIAN ROCKS IN THE ENGLISH BOULDER-CLAYS. 
Sir,—In connection with the subject raised by Herr Madsen’s 
recently published paper on ‘Scandinavian Boulders at Cromer,”? 
it may be of interest to give a list, brought up to date, of the 
Norwegian rocks which I have examined from the Boulder-clays 
of Holderness. 
(i). Augite-syenite (‘laurvikite’ of Brogger) from the neighbourhood 
of Laurvig. 
(ii). ‘ Rhombenporphyr’ of Kjerulf and others, from the Christiania 
district. 
(iii). ‘Saussurite-gabbro,’ as described by Mohl and Reusch from 
the west coast of Nor way ; two or three varieties. 
(iv). A rather coarse red granite with much microcline and micro- 
perthite and subordinate dark mica. This agrees well with the 
rock described by Brégger from the Christiana district, but 
I have no specimens for comparison. 
(v). Various grey granites with dark or with both dark and white 
micas, corresponding to those largely developed in the ‘ Grund- 
fjeld’ of Norway. These, unlike the preceding, always show 
cataclastic structures, strained quartz, etc. 
(vi). Well-banded gneisses, the coarser ones hornblendic, the finer 
micaceous. 
(vii). Various hornblende-schists and mica-schists, the latter often 
garnetiferous. These and the gneisses it would be impossible 
to refer to precise localities, but their Scandinavian origin can- 
not be doubted. ALFRED Harker. 
St. Joun’s Counecr, CAMBRIDGE. 
Str,—There is a curious error, which by some oversight has crept 
into my letter in the February Number of this Magazine. The 
sentence—‘“Creditably again is so variable a factor,” etc. (which 
makes nonsense) should read “Credibility,” as it stands in the 
rough MS. which I have by me. Most readers of the Grox. Mag. 
have probably made the correction fer themselves. A. IRVING. 
WELLINGTON CoLtLEGE, Brrxs, 4 Feb, 1893. 
TITLES OF SEPARATE COPIES OF SCIENTIFIC PAPERS. 
Str,—A few years ago I advocated in your pages a reform in 
regard to the titles of separate copies of scientific papers: its 
adoption encourages me to venture further suggestions on the same 
lines in regard to the volumes themselves. My suggestions are :— 
1 Q.J.G.S. vol. xlix. p. 114, 1893. 
