they are not molluscous animals. I read your letters last night, this
morning I took a little walk; by a curious coincidence, I found a new white
species of Planaria, and a new to me Vaginulus (third species which I have
found in S. America) of Cuvier. Amongst the marine mollusques I have seen
a good many genera, and at Rio found one quite new one. With respect to
the December letter, I am very glad to hear the four casks arrived safe;
since which time you have received another cargo, with the bird skins about
which you did not understand me. Have any of the B. Ayrean seeds produced
plants? From the Falklands I acknowledged a box and letter from you; with
the letter were a few seeds from Patagonia. At present I have specimens
enough to make a heavy cargo, but shall wait as much longer as possible,
because opportunities are not now so good as before. I have just got scent
of some fossil bones of a MAMMOTH; what they may be I do not know, but if
gold or galloping will get them they shall be mine. You tell me you like
hearing how I am going on and what doing, and you well may imagine how much
I enjoy speaking to any one upon subjects which I am always thinking about,
but never have any one to talk to [about]. After leaving the Falklands we
proceeded to the Rio S. Cruz, following up the river till within twenty
miles of the Cordilleras. Unfortunately want of provisions compelled us to
return. This expedition was most important to me as it was a transverse
section of the great Patagonian formation. I conjecture (an accurate
examination of fossils may possibly determine the point) that the main bed
is somewhere about the Miocene period (using Mr. Lyell's expression); I
judge from what I have seen of the present shells of Patagonia. This bed
contains an ENORMOUS field of lava. This is of some interest, as being a
rude approximation to the age of the volcanic part of the great range of
the Andes. Long before this it existed as a slate and porphyritic line of
hills. I have collected a tolerable quantity of information respecting the
period and forms of elevations of these plains. I think these will be
interesting to Mr. Lyell; I had deferred reading his third volume till my