ANNIVERSARY ADDRESS OF THE PRESIDENT. XXX1 
this country by Mr. Lyell. He enumerates—1. Teniopteris magni- 
folia (a fern first noticed by Prof. Rogers) ; 2. Neuropteris linnee- 
folia (n. sp.) ; 3. Pecopteris Whitbiensis ; 4. Pecopteris (Aspidites) 
bullata (nu. sp.); 5. a questionable Pecopteris; 6. Filicitus fim- 
briatus ; 7. Equisetum columnare ; 8. Calamites arenaceus (Rogers) ; 
9. another Calamite, probably the young plant of the above; 10. Zamites 
obtusifolius (Rogers); 11. Zamites gramineus (n. sp.?); 12. a 
questionable Sigillaria or Lepidodendron ; 13. casts of small portions 
of a decorticated stem a little like those of some Lepidodendra; 14. a 
doubtful Knorria ; and 15. indeterminable fragments of a plant ap- 
parently with verticillated grass-like leaves. Figures accompany the 
descriptions Nos. 2, 4 and 6 of the above-mentioned fossil plants. 
To Sir Philip Egerton, who has so successfully studied fossil fish, 
the Society is indebted for a communication on the Nomenclature of 
the Fossil Chimeeroid fishes, in which he rectifies errors previously 
committed, and proposes to divide these fossil fishes into four genera, 
namely Ganodus (Egerton), Ischyodus (Egerton), Edaphodon 
(Buckland), and Hlasmodus (Egerton). The first genus contains 
ten species, all from the Stonesfield oolite ; the second nine species, 
from the chalk marl and greensand, the gault, the Portland beds, 
the Kimmeridge clay, the Caen oolite, and the las; the third 
genus contains seven species, from the Bagshot sands and Bracklesham 
beds, the molasse of Switzerland, the chalk, and greensand ; the fourth, 
two determinable and one unnamed species, from the Sheppey and 
Bracklesham beds, and from one unknown locality. Thus, these 
remarkable fishes have existed from the time of the lias to the 
present day, and the researches of Sir Philip Egerton have shown 
their range through geological time, established three new genera, 
and added no less than thirteen new species to the same number of 
species previously figured or described by Dr. Buckland, Prof. 
Agassiz, and Prof. Owen. 
In his microscopical observations on the structure of the bones of 
Pterodactylus aiganteus and other fossil animals, Mr. Bowerbank 
gives a detailed account of his researches into the forms of the bone-cells 
of man, and of recent or fossil birds, reptiles and fishes, and considers 
that these forms furnish characters sufficiently distinct to permit their 
classification ; thus while the proportion of the length to breadth 
in the bone-cells of man are represented to be as 1 to 4, that of the 
albatros is as 1 to 64, of a fossil bone of a bird from the Wealden 
1 to 51, of the Thylacotherium Prevostii 1 to 44, of the common 
frog 1 to 113, of the Boa constrictor | to 11, and of a Pterodactyle 
jaw 1 to 11: other examples are given, as also considerable detail, 
requiring the plates for their proper appreciation. Mr. Bowerbank 
considers that the aid of the microscope may thus be most advan- 
tageously employed to determine the class of animals to which doubt- 
ful fossil bones may belong. From his researches he refers certain 
bones from the chalk, considered to be those of birds, to the Ptero- 
dactyle, and states that they confirm the views taken by Professor 
Owen respecting the mammalian character of the disputed remains 
discovered in the Stonesfield slate. 
