echinoderms from west australia. 235 
Oligometra serripinna. 
Antedon serripinna P. H. Carpenter, 1881, Notes from the Leyden Museum, vol. iii. 
pp. 175, 183. 
Oligometra serripinna A. H. Clark, 1908, Proc. Biol. Soc. Washington, vol. xxi. p. 126. 
At Ijong Island a single small specimen o£ this comatulid was taken, but 
it is not typical. The ridge across the segments o£ the cirri is very incon- 
spicuous, an'd none of the pinnule segments have conspicuous projections. 
"There are ten arms about 35 mm. long, and the cirri are XII, 17. Pi has 10 
segments, P2 has the same number but is conspicuously bigger, while P3 also 
has 10 segments and is about equal to Pi< In colour the general impression 
is olive-cream and purple, the former being the ground-colour. There is a 
distinct wide purple line up each side of Brj and Bj basally, but this soon 
breaks up into spots, and disappears in the joints or in lines across the 
segments at their margins. There is no regularity of arrangement. 
The occurrence of serripinna at the Abrolhos is unexpected, as it has not 
been hitherto recorded from Australia, but Mr. A. H. Clark considers this 
.specimen undoubtedly Carpenter's species and not 0. carpenteri Bell, which 
has been recorded from northern Australia several times. (A. J. D.) 
ASTEROIDEA. 
Astropecten preissii. 
Miiller & Troschel, 1843, Arch. f. Naturg., jhrg. ix. 1, p. 119. 
There are three Astropectens, dredged off Fremantle, which seem to be 
undoubtedly this species. They have lost all indication of their original 
colour and are now dingy light-brown. The smallest has R = 30, r = 6, and 
br = 6"5 mm. ; thus R = 5 r. Superomarginal plates all unarmed. Infero- 
marginals with a single wide, flat, pointed marginal spine, below which are 
two very much smaller and more slender spines, of which the adoral is 
smaller ; about four somewhat smaller spines form a longitudinal, well- 
spaced series on the ventral surface of the plate. A second specimen has 
' R = 70, r = 10, and br = 13 mm. ; hence R = 7 r. On one arm three of the 
distal superomarginals bear small but distinct spinelets. The armature of 
the inferomarginals is essentially as in the young individual, but the marginal 
spines and those below are markedly heavier.. The third specimen has 
R — 120, r = 15, and br = 17 mm. ; hence R = 8 r. There are no supero- 
jnarginal spinelets, and the inferoinarginal armature is also quite typical. 
LUII>IA MACDLATA AUSTRALIA. 
Luidia australice Dbderlein, 1920, ' Siboga ' Ast. pt. ii. Luidia, p. 266. 
An adult specimen, taken near Fremantle, has the usual seven raj's, and 
■the measurements are R = 225, r = 29, and br = 31 mm. The distal 
paxillse are characteristically large, and there are some pedicellarise on the 
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