Gleanings. 229 
2. What I considered as fossil seeds were said to be mere pea- 
cock-eye coal; the dark carbonaceous centres of these seeds, 
which I held to be carbonized cellular matter, was thought to be 
a mere mistake, and the seeds imaginary. I have since discover- 
ed them with distinct and clear apparently spinous appendages. 
Mr. Agassiz thinks the seed a samara, and I have found sufficient 
quantity to pick out the carbonaceous matter from the interior 
with a tine needle, decarbonize it in a clean plalina crucible, over 
a spirit lamp, with every possible precaution to prevent any 
foreign substance mixing therewith; on examining this with the 
oberhausen, 700 diameters, Mr. Agassiz showed to Dr. Gould and 
myself the cells as clear and plain as possible; it is a mass of 
cellular matter, as I stated. You may of course imagine the ex- 
treme tenuity of the parietro of seeds w^hen decarbonized, and the 
difficulty of those less experienced than Agassiz in the microscope 
in managing the subject; he feels quite convinced of their being 
fossil seeds. The nature of the genus of plants must require fur- 
ther examination. 
3. The smooth glossy surfaces which I considered the external 
parts of large plants rendered smooth by intense pressure, were 
said to be nothing more than slicken slides. My position here is 
proved much more easily than in the other cases, by specimens 
passing gradually from the smoother through different degrees of 
protruberance, (all still smooth and polished,) until we arrive at 
the full form of the Lepidodendra. Nay more, I have found the 
parallel lines (channels) which are on the slicken slides, also on 
the perfectly formed Lepidodendra. The correctness of my views 
here I could prove to the most sceptical. 
Basilosaurus — (Communicated by Prof. Agassiz, from a letter 
recently received from M. A. Retzius.) — The following is an ex- 
tract from a letter from Prof. J. Muller to M. A. Retzius, dated 
Berlin, March 24, 1847: 
The Hydrarchus,'Koch, found in the tertiary formation in Ala- 
bama, is identical with Harlan's Basilosaurus and Owen's Zeu- 
glodon cetoides.* The crowns of the teeth, with which Owen 
was not acquainted, have a great resemblance to those of the seal; 
in the maxillary teeth they are cutting and many pointed; most 
of the maxillary teeth have double roots, but the anterior h.^s, as 
in the seals, only a single root. In the anterior part of the jaw 
are found conical curved teeth, viz: an incisive or canine, at least 
this is the case with the under jaw. 
As such teeth as those which are found in the Hydrarchus, oc- 
cur in the tertiary formation in matter, we may conclude that this 
animal belongs likewise to the tertiary of that island. 
I think I can positively show that the Hydrarchus is not a rep- 
