266 IX MEMORIAM : WALTER PERCY SLADEN, F.L.S., F.G.S., F.Z.S. 
the Journal of the Linnsean Society a communication on the 
Asteroidea of H.^SI.S. " Challenger a description of Jlimaster, 
a new genus from the Faroe Channel ; the British Association 
Report on the Scottish Zoological Station (1881-2-3) ; and 
a monograph of the Tertiary Echinoidea of Kachh and Kattywar 
appear the same year. In 1884 he wrote on the homologies of 
primary larval plates, of the test of Brachiate Echinoderms, and 
on the classificatory position of Hemiaster elongatus. In 1885 
appears in the narrative of the cruise of H.M.S. "Challenger" 
a general summary of the Asteroidea collected during the 
expedition, and a paper in the Linnean Society's Journal on the 
family Arbaciadce. In 1886 he continued bibliographical notices 
on the Crinoidea, etc., which were commenced the previous 
year ; issued his monograph of the Fossil Echinoidea of the 
coast of Beluchistan (Palieontologia Indica) ; and a paper on the 
anatomy of the perignathic girdle and other pai-ts of the test of 
Discoidea cyliiidrica. In 1887 he published in the Annals and 
Magazine of Natural History his views on some points in the 
morphology and classification of Saleniidce. In 1888 were given 
in the same magazine his objections to the genera Pseudophy- 
gatdus, Trachyaster, and Ditremaster. In 1889 appeared the 
Report on the Asteroidea collected by H.M.S. " Challenger " 
during the year 1873-1876. We do not pretend to estimate the 
scientific value of this truly superb work, but content ourselves 
with quoting from one far better qualified by his critical ability 
to do so : — " This magnificent work of 900 pages, with its 
accompanying atlas of 118 plates, ranks among the most masterly 
and exhaustive of the ' Challenger ' volumes. Before taking it 
seriously in hand, Sladen visited every museum in Europe (with 
one exception) which was known to contain star fishes of 
importance ; and, as pointed out by the editor in its preface, it 
is a monograph of the whole group. The labour involved in its 
production was prodigious ; and its interest is enhanced by the 
fact that the bulk of it was written between the hours of 
9 p.m. and those of early morning, often after a day's occupation 
with other affairs. The extension of the family Pterasteridse 
