146] 
RECORDS OF W.A. MUSEUM. 
extend from the actinolaterals (beginning with the third) to the 
margin. At the margin of each interradial area, the regular serial 
arrangement of actinal plates is interrupted by the intercalation of 
small rounded or polygonal plates, some of which also crowd in 
between the lower ends of the inferomarginals. 
Adambulacral plates short and not very wide ; there are about 
two to each actinolateral plate. Armature in a double series ; inner 
of 7-9 rather slender spines, parallel to furrow, median longest and 
adoral and aboral shortest and subequal ; outer of two or three very 
short blunt spines about 2 mm. long and 1-2 mm. thick, on actinal 
surface of plate, parallel to furrow, median (or adoral of two) longest 
and stoutest. Oral plates with about a dozen spines on each mar- 
gin ; proximal very large, 7 or 8 mm. long, 3 or 4 mm. thick at tip ; 
distal spines smaller : distalmost grading into inner series of first 
adambulacral plate ; each oral plate bears on its surface 3 or 4 very 
stout, low spines, similar to those of the outer adambulacral series. 
Pedicellariae abundant on actinal surface, but not observed in 
this specimen abactinally. On adambulacral plates are very heavy 
spatulate pedicellariae with two jaws ; these are at adoral end of 
plate and may be one, two or three in number ; if there are two or 
three, one is usually much the largest. Scattered all over the 
actinal interradial areas, but most abundant on the radial ends 
of the actinolateral plates are bivalved pedicelloriae with jaws a 
millimetre wide or less. 
Colour above, light grey ; actinal surface more yellow-brown. 
There are no data with this extraordinary starfish, but it is said 
to have been taken on the coast of West Australia. It is difficult 
to understand how so large and conspicuous a form should have so 
long been undescribed, but lean find nothing in the literature which 
would warrant the belief that specimens had ever been seen by 
European zoologists. The swollen circular disk beyond which 
project the short stumpy rays give the animal a very odd appear- 
ance, while the regular actinal plating covered with a closely 
granulated membrane is remarkably distinctive. 
There can be little doubt that the genus is intermediate be- 
tween Oreaster and Culcita. 
