1907.] Annwersary Address by Lord Rayleigh. 81 
‘Differential and Integral Calculus which is now in progress; his Presidential 
Address to the London Mathematical Society, in 1902, on the questions here 
arising, aroused general interest among mathematicians; and he has recently 
(1907) published an extensive volume, dealing with the whole matter and its 
applications to the theory of Fourier’s series, which is of great importance for 
the history and development of Mathematics. 
His Majesty has also approved the award of a Royal Medal to Dr. Ramsay 
H. Traquair, F.R.S. . 
Dr. Traquair is honoured on the ground of his long continued researches on 
the fossil fishes of Paleozoic strata, which have culminated, within the past 
10 years, in his discovery of new groups of Silurian and Devonian fishes, and 
in his complete exposition of the structure of Drepanaspis, Phlyctenaspis, and 
other remarkable forms. | 
For nearly forty years Dr. Traquair has been busy with the description of 
fossil fishes, mostly from the Paleozoic rocks of Scotland, and he is deservedly 
held to be one of the most eminent paleontologists of the day. He has been 
highly successful in the interpretation of the often very obscure and frag- 
mentary remains which he has had to elucidate, and his restorations of fishes 
_ have won such credit as to appear in all modern text-books of Paleontology. 
It may be said that his work, notwithstanding the great difficulties of the 
subject, has well stood the test of time. 
Dr. Traquair has done much to advance our knowledge of the osteology of 
fishes generally. His earliest memoirs on the asymmetrical skull of flat- 
fishes and on the skull of Polypterus remain models of exactness. His 
acquaintance with osteology enabled him to show how former superficial 
examination of the Paleozoic fishes had led to wrong interpretations. He 
demonstrated that Chirolepis was not an Acanthodian, as previously supposed, 
but a true Paleoniscid. In 1877 he satisfactorily defined the Paleeoniscidée 
and their genera for the first time, and conclusively proved them to be more 
nearly related to the Sturgeons than to any of the other modern Ganoids 
with which they had been associated. He thus made an entirely new 
departure in the interpretation of extinct fishes, replacing an artificial 
classification by one based on phylogenetic relationship. His later memoir 
on the Platysomidee was equally fundamental and of the same nature. 
All subsequent discoveries, many made by Traquair himself, have confirmed 
these conclusions, which are now universally accepted. 
In 1878, Dr. Traquair demonstrated the Dipneustan nature of the Devonian 
Dipterus, and somewhat later he began the detailed study of the Devonian 
fishes. His latest researches on the Upper Silurian fishes of Scotland are 
equally important, and provide a mass of new knowledge for which we are 
