Correspondence—Ur. C. Davison. AT 
paper. The reason for correlating the Longmynd rocks with the 
Upper Monian are, first, that they are certainly pre-Cambrian, 
especially since the discovery by Prof. Lapworth of the lowest 
Cambrian fauna in other rocks in the immediate neighbourhood, 
and, secondly, that the only certain fossils recorded from the Long- 
mynd, Arenicolites didyma, are also recorded from the rocks of Bray 
Head. It is also to be noted that as the “ Uriconian”’is to a large 
extent volcanic, there need not be much of a gap between it and 
the “ Longmyndian.” By some curious effort of the imagination 
Dr. Callaway says “‘ Uriconian and Malvernian are lumped together 
as Middle Monian,” but I cannot find that I have anywhere mentioned 
the ‘“ Malvernian,” as I know too little of that district and the 
descriptions are too discordant to make it safe even to venture upon 
a probability. It may not be Monian at all. 
If Dr. Callaway has a fancy to call the different divisions of the 
Monian by names derived from other districts, there can be no 
objection, provided we first make sure of the correlation. J am 
perfectly satisfied with their all forming parts of a larger group or 
system—the Monian. 
I may add that as these rocks have a quite distinct character from 
the true Hebridean, or the general type of gneisses, I was much 
delighted to find that so many foreign geologists, who visited Anglesey 
in September last, recognized their resemblance to rocks of their 
several districts which occur immediately beneath their lowest 
fossiliferous horizons. J. F. Bras. 
Dec., 1888. 
UNIFORMITY IN SCIENTIFIC BIBLIOGRAPHY. 
Srr,—Having been for some time engaged in preparing a biblio- 
graphy of earthquake-literature, I can fully endorse the necessity 
of Mr. C. D. Sherborn’s plea for uniformity in the quotation of 
abbreviated titles of scientific journals. The increasing number and 
importance of works of this class render this and other unsettled 
points in bibliography worthy of attention and discussion; and I 
would venture to suggest that the British Association Committee on 
Zoological Nomenclature could find a useful successor in a Committee 
for securing Uniformity in Scientific Bibliography. 
May I be allowed to offer here a few remarks on this subject ? 
Abbreviated Titles.— Besides a mere hap-hazard choice two courses 
are open in the selection of abbreviated titles. 
(1) We may adopt that in use amongst the members of the 
Society issuing the journal, as “ Phil. Trans.” or “Comptes Rendus.” 
Familiarity in a few cases and established custom are in favour of 
the retention of this system, but it has the obvious disadvantage of 
not representing at a glance the complete title of an unknown 
journal, for it omits the name of the society. Moreover, contractions 
founded on such words as “Transactions” or ‘ Proceedings,” 
common to a great number of societies, are objectionable. 
(2) The abbreviations may be formed on a uniform plan from the 
full title of the journal. That adopted in the Geological Record 
