INTRODUCTION. XVl 
mainly with recent forms, but discussing also the fossil Owlopleuri; two minute 
examinations of the anatomy of Discotdea cylindrica (31 and 34), a common fossil in the 
Upper Chalk ; and a note on the “‘ Morphology and Classification of the Salenide ” (32) ; 
but though these, by reason of the amount of detail they contain, are of importance to 
students of fossil Echinoidea, they call for no special notice here. 
Sladen’s methodical habits and invariable courtesy and unselfishness rendered him 
peculiarly fitted to occupy official posts in the Societies to which he belonged ; thus in 
Halifax we find him acting as Secretary to the local Literary and Philosophical Society, 
and as Honorary Curator of the Halifax Museum. In connection with the British 
Association he was Secretary of the Committee of the Scottish Zoological Station from 
1881 to 1883; and Secretary of the Committee of the Zoological Station at Naples from 
1879 to 1898. He became a Fellow of both the Linnean and Geological Societies in 
1876, but it was not until after his removal from Halifax to Ewell in 1883 that he 
became intimately more associated with the former Society, on the Council of which he 
served almost continuously from 1884 to the time of his death. He was also Zoological 
Secretary of the Linnean Society from 1885 to 1895, and Vice-President for the year 
1895. 
Cheerful, humorous, and of a remarkably even temper, Sladen presented to his many 
friends a singularly lovable nature, in which unselfishness, sincerity, and a generous 
appreciation of the work of others were some of the leading characteristics. Of his 
many acts of private charity it is impossible to say much, as few except the actual 
recipients were ever allowed to hear of them; but his gift of £2000 to insure the lives 
of the Devonshire Yeomanry and Volunteers, when they went to the front in the Boer 
War, stands forth as a public record of his liberality and patriotism. 
Although in the interests of the science which he loved his work was confined within 
a narrow field, he was a man of great general cultureand attainments. As a linguist he 
excelled, and to an intimate knowledge of the leading European tongues, he added a 
good acquaintance with Persian literature. But his favourite pursuit, apart from his 
actual work, was the study of old books and manuscripts; these he seldom lost an 
opportunity of examining in public and private libraries, and his own collection, though 
it could hardly be called extensive, contained some rare and highly prized specimens. 
His marriage in 1890, with Constance, daughter of the late William Charles Anderson, 
Senior Justice of the Peace for York, when both had arrived at middle age, was a source 
of deep happiness to him. Community of tastes in literature and art, together with that 
rare sympathy which instinctively avoids all sources of difference, rendered their union 
one of exceptional harmony; the more so, perhaps, because, owing to Sladen’s stern 
sense of duty, the consummation of their devotion had been postponed for nearly twenty 
years. But at last the guardianship and education of his step-brothers and sisters, 
on which he had bestowed such self-sacrificing care, came to an end, and enabled him 
to leave Ewell and settle in London, the place best suited for that scientific work which 
he promised himself now to pursue with even greater energy than before. 
This hope, alas! was destined never to be fulfilled. Sladen had for several years been 
working with a strenuous application that could not but leave its mark upon an already 
