238 Dr Fleming on the British Testaceous Annelides. 
is a very remarkable fact. The magnetic pole in North America 
approaches slowly towards the east ; and ought, therefore, if the 
foregoing possibilities have any reality, in the succession of ages, 
to surround the northern part of our peninsula with the same 
barrier, by which it has for ages shut out the east coast of 
Greenland from all participation in the commotions of Europe. 
However desirable this might be in some respects, we cannot 
help wishing, on other accounts, that this prediction may turn 
out like other prognostications of the weather. 
Art. V. — On the British Testaceous Annelides. By the Rev. 
John Fleming, D.D. F.R.S.E. M.W.S. Minister of Flisk. 
(Communicated by the Author.) 
-A. CONSIDERABLE degree of uncertainty seems to prevail with 
regard to the number of species of the Testaceous Annelides at 
present inhabiting our seas, and the antiquity of those which oc- 
cur in a fossil state. 
Among the recent species, there are a few which inhabit sta- 
tions accessible to the diligent inquirer, and afford opportunities 
for investigating their structure. Others, however, live in deep 
water, and are seldom found in a condition fit for anatomical 
investigation. Even among those which can be procured in a 
living state, the few which are of ordinary occurrence present, 
in their diminutive size, formidable obstacles to the knife, or 
even the needle and microscope of the physiologist. Nor is 
it to be concealed, that British naturalists have, in too many in- 
stances, confined their attention to the characters furnished by 
the shell, while they have overlooked or undervalued those which 
are exhibited by the other organs of the animal. 
The history of the extinct species which occur in our rocks, 
appears likewise to be involved in considerable obscurity. There 
is so little variety in their form and markings, that it becomes 
extremely difficult to establish definite specific characters. Our 
principal > reliance must therefore be placed on the accuracy of 
our knowledge with regard to the strata in which they occur, 
and we must endeavour to derive assistance equally from the 
zoologist and geognost. A few months ago, an eminent English 
naturalist expressed a wish to know the evidence upon which I 
