Strata, Shells, 8c. of Durham, Northumberland, &c. 49 
portant helps towards identifying the Sirata, where their actual 
continuity, or sufficient of the series of Strata being visible, are 
wanting, for so indicating identities; even, by those Observers, 
who, however well and usefully, they may-know Shells, by their 
appearances, when carefully compared with each other, yet possess 
no technical or conchological knowledge, for enabling such per-' 
sons, to name or describe Shells, in Language or in Drawings, 
which would be definite, or satisfactory, to general Naturalists, 
as was the case with Mr. Wm. Smith, the Mineral Surveyor, 
during many of the first years he was employed, in collecting and 
arranging, many hundred Shells, and other species of Organic 
Remains, each Specimen properly referred, to its local seat and 
stratum ; which Specimens, now, that they are lodged in the 
British Museum, for the free use of the Public, others can, with 
the greatest facility and satisfaction, depict, name and describe, 
with all due technical accuracy. 
I have mentioned thus much, in hopes of inducing Mr. Forster 
in future, to imitate Mr. Smith herein, as far as his opportunities 
of seeing fossil Shells may extend; and, in order to refer him to 
a Paper on this subject, which you did me the favour to insert 
at p. 274 of your xlvth volume: and particularly, to request his 
answers to my 3d head of Queries, already referred to. 
_ It has given me pleasure, and I doubt not will do so to many 
_of your Readers, to see, that Mr. Forster is able, so importantly 
.to vindicate the character, for accuracy, of the Section of the 
Straia, which he published in the year 1809, as already men- 
tioned, as to assert, that all the latter and lower parts of the 
‘same, were entirely made from his own observations and admea-~ 
surements, at several mining fields, and bassets of the strata: and 
I beg to remark, that Mr. F. would confer a further and lasting 
obligation, if he would send for insertion in your Magazine, an 
account of the steps which he took, whether by comparing the 
overlapping or repetition of his Strata, measured in different 
Mines, Works, or Places, or otherwise, for avoiding errors, in 
joining these detached olservations together ?: a point on which, 
{ think I remember having read the expression of some doubts, 
particularly as to the junction of the Lead-Series and the Coal- 
series, in some former volume of your Work, but which at pre- 
sent I am unable, more particularly to quote. 
Mr. Winch, Mr. Fryer, Mr. Buckland, &c. to whom my 
Queries referred to, were in the first instance more particularly 
addressed, will I hope and trust, excuse the reference adso, of the 
same queries to Mr, Forster, so expressly as has now been done ; 
and that the same, may not lessen the chances we had, of any 
answers thereon, from all or any of these Gentlemen, to whom— 
Vol. 50. No,231, July 1817. D Mr, 
