333 Editorial Notes. 
word. The essential feature of a true grit is that it should be 
gritty, that is, breaking and weathering with a rough uneven surface, 
which these rocks do not. A true grit, such as the Millstone Grit, 
is of very irregular grain, and usually more or less porous, whereas 
the Silurian rocks here referred to are of very fine texture, even- 
grained, and very closely and tightly cemented. The name sand- 
stone is hardly applicable, since to most people it connotes the idea 
of a somewhat soft and crumbly rock. The old term greywacke 
- is better, but unfortunately it is not English. What is wanted is a 
good Anglo-Saxon word, not already used in some other quite 
different sense, and if possible self-explanatory. During the present 
field-season we commend this problem to our readers, and shall 
be glad to receive any communications on the subject that may 
suggest themselves. There are other problems of a similar nature ; 
for example, What is a quartzite? Is a marl necessarily calcareous ? 
And so on. Many more will no doubt occur to our readers. How- 
ever, let the discussion, if any, be confined to one at a time. 
It is quite obvious that in geological research work two sets of 
names are required. One, of a rough and ready character, for use in 
the field ; the other, for detailed petrographical descriptions in the 
laboratory. Among the igneous rocks we have excellent examples 
of the first class in the good old names felsite and greenstone. It is 
true that felsite is a barbarous word, but it is consecrated by usage, 
while greenstone is eminently descriptive, and both are well adapted 
for field notes. Later on, the rock can be examined and analyzed 
and assigned to its proper pigeon-hole in the system of petrographic 
nomenclature specially fancied by the writer. Most of the common 
names for the sediments do fulfil the requirements of field-work, 
but there are not quite enough of them, so that many are used in 
more than one sense. Every one is acquainted with the trouble 
caused by endeavours to find out what is really meant by schiste and 
Schiefer, and the two senses of the word cleavage are a perpetual 
stumbling-block to beginners. We are far from wishing to increase 
the number of technical words or of words used with technical 
meanings in addition to their ordinary significance, but it is evident. 
that a few more are really needed. 
