IX MEMORIAM : WALTER PERCY SLADEX, F.L.S., F.G.S., F.Z.S. 267 
and the great addition to our knowledge of the deep sea forms 
are its most sahent characters ; but we know not which to 
admire most, the body of the work, with its laborious descriptions 
of individual forms, or the supplemental part, in which there 
is given a list of every known species, with a record of its 
bathymetric distribution. Elementary student and expert stand 
alike indebted to him for this monumental work, indispensable 
to progress in the knowledge of the subject wdth which it deals. 
Generic names like Benthaster and Marsipaster are sufficiently 
significant in themselves. Proceeding to classification, Sladen made 
good use of the marginal and ambulacral plates, and his sub- 
division into the sub-classes Euasteroidea and PaUeasteroidea, with 
the ordinal divisions to which he was led, has withstood the test 
of time, and become the adopted classification of the better text 
books, as for example those of Lang and Gregory. In this his 
influence on the progress of science will live, and it is a matter 
of profound gratification that only a short time before his death 
he gave expression to the satisfaction this afforded him." 
His last memoirs were published in the Palseontographical 
Society's volumes for 1890 and 1893, and were on the Cretaceous 
Asteroids. 
In the year 1890 he married Constance, elder daughter of 
the late Dr. W. C. Anderson, of York, a union of heart and 
mind, }delding a bright and tender sympathy which strengthened 
and stimulated him in his life's work. On 14th February, 1898, 
his uncle, Mr. John Dawson, died, leaving him Xorthbrook, his 
beautiful home in Devonshire. 
The friends of Sladen's youth and early manhood appreciated, 
as indeed all who were brought in contact with him must have 
done, his clear and logical powers of mind and refined nature; 
amongst the Yorkshire naturalists who met him again and again 
in scientific fellowship and communion, his judgment was highly 
prized : the late J. W. Davis, F.G.S., his friend and neighbour, 
Thos. Hick, B.A., B.Sc, John Stubbins, F.R.M.S., Geo. Brooke, 
F.G.S., G. H. Parke, F.L.S., C. P. Hobkirk, F.L.S., and W. Cash 
were amongst this privileged band. 
