SLADEN TRUST EXPEDITIONS TO ABROLHOS I8LAKDS. 21 
THE PERCY SLADEN TRUST EXPEDITIONS * TO THE ABROLHOS 
ISLANDS (Indian Ocean). 
Under the Leadership of Prof. AV. J. Dakin, F.L.S, F.Z.S. 
On Two Sea-pens from West Australia. By Sydney J. Hickson, F.R.S., 
Professor of Zoology, University of Manchester. (Comnninicated by 
Prof. W. J. DakIxN, F.L.S.) 
[Read 5th May, 1921.] 
At the present time only three species of Pennatnlacea have been recorded 
from the waters of the Western coast of Australia, and these were all found 
in Shark^s Bay, over 200 miles north of the locality from which the two 
species here recorded were obtained. The species previously recorded are 
Policella australis by Gray (1862), Virgidaria elegans by Gray (1870), and 
Pteroides hijmenocaulon by Broch (1910). 
The two specimens obtained hy Professor Dakin from the neighbourhood 
of the Abrolhos Archipelago belong to, or are closely related to, species that 
are found in the Malay Archipelago ; but as other species of the same genera, 
namely Veretillum cynomorimn and Pteroeides griseimi, occur in the Mediter- 
ranean Sea, and the genera are widely distributed iu shallow to deep water, 
the presence of the two sea-pens off Abrolhos is a fact of no value, at present, 
for the determination of the affinities of the local fauna. It is quite possible, 
or even probable, that they have travelled down from the North, but it would 
not be surprising to find them a great deal further South, as they are not 
tropical forms. 
Veretillum malayense (Hickson) f. 20 fathoms. Off Long Island. 
Length of rachis 80 mm., length of stalk 60 mm., diameter of rachis and 
of stalk 12 mm., diameter of terminal bulb 11 mm. Autozooids 14 mm. in 
length by 2' 5 in diameter. 
The rachis is club-shaped, but differs from the rachis of the type-specimen 
in coming gradually to a blunt extren)ity. The stalk lias a well-marked 
* Ackuowledgemeut must be, made here also of a grant from the Government Grant 
Committee of the Royal Society, and a grant from the British Association. 
t 'Siboga ' Pennatnlacea, 1916, p. 48. 
