478 MELVILL: THE PRINCIPLES OF NOMENCLATURE. 
‘“‘riders ” which might, I think, with reason be considered in 
future as binding upon all describers of shells :— 
(a) That no new species should be given to the world without 
being also figured in a proper and intelligible manner. 
(6) That, if possible, the type specimen should ultimately, if 
not immediately, be relegated to the principal museum of 
that country to which the author belongs. 
(¢) That no periodical should be allowed to issue its number 
bearing a date that is not the actual date of publication, 
With quarterly serials it occasionally happens that, for 
some reason or other, the subject matter gets into arrear ; 
and in one particular case the said serial is just now nine 
months late, and, notwithstanding this, it continues to 
publish sp. nov. as with the earlier date of issue. ‘This, it 
will be seen at once, may bring insuperable difficulty into 
the field, as regards the law of priority. 
XIV.—SUMMARY. 
Lastly, it is satisfactory to be able to record that, at 
all events, generically speaking, the nomenclature of Malaco- 
logical science is founded upon a very strong and, practically, 
unassailable basis. Speaking sfecifica//y, the question is, as I 
have already remarked, not to be so easily solved, but, at the 
same time, it must be argued with some degree of assurance 
that those few genera which have been most minutely mono- 
graphed during the past few years, with every attention given 
to priority in specific names, have passed through the ordeal 
with comparatively little change. It augurs well for the 
remainder. 
It is to be hoped, however, that a still greater ‘‘ rapproche- 
ment ” than has hitherto existed will be brought about between 
the students of recent and of fossil mollusca. Thanks, especially, 
to the Malacological Society of London, this is being arranged 
JG, vin; Oct. x807. 
