614 
SUPPLEMENTARY NOTES. 
Vol. IV, p. 15.) but that the Beds called Top Cap, immedi- 
ately beneath the Dirt Bed (see PI. 57, Fig. 1.) are of Fresh 
water origin. Beneath this Top Cap, two other seams of black 
earth of very small extent and thickness, one about five feet and the 
other seven feet below the Dirt Bed, were discovered in 1832, by 
Prof. Henslow, (Geol. Trans. N. S. Vol. IV. p. 16), and in the 
uppermost of these Dr. Fitton has since found trunks of Cyca- 
dites, in the position which they would have occupied if they had 
grown there. (See Geol. Trans. N. S. V. iv. p. 219.) 
P. 499. In the course of the last year, Mr. Robert Brown has 
ascertained by examination of a Trunk of Cycadites microphyllus, 
from Portland, the existence of scalariform vessels without 
discs, in the mature Trunk ; a point in which, he informs me, 
these fossils agree with the American portion of the order Cyca- 
dem, though, in other respects, they bear a greater resemblance 
to the African and Australian species. Mr: Brown observes 
further, “ that the order Cycadem presents but one genus in 
America, namely, the Zamia, on which this genus was originally 
founded, and to which it has been recently restricted ; and that 
the coincidence in the structure of the scalariform vessels in 
the trunk of this Zamia of the New World, with that of the 
fossil Cycadites of Europe, is very remarkable. 
P. 519. Note, 1. 16. Since the Publication of my first Edi- 
tion, I have been favoured with the following communication 
from Mr. Bowerbank, respecting the fossil remains of vegetables 
found in the London Clay. “ I have, in my collection of fossil 
fruits from the London Clay, more than 25,000 specimens. The 
species I have already determined exceed 500 in number, and I 
have no doubt that several hundred more may be estimated at 
the true number in ray collection. The late Mr. Crow informed 
me that he was acquainted with between 6 and 700 species. 
None of these fruits can be with certainty referred to any recent 
species, although the approximation is in many instances very 
close. Palmaceous fruits are abundant, and many other fruits 
agreeing not only in external form, but in internal structure with 
well known classes of seed-vessels of the present period; along 
