SEA LILIES, STARFISHES, ETC.—CLARK. 67 
intermediate plates, few and scattered, with 6-12 spinelets ; 
actinolateral plates very few, small and scattered, with very 
few spinelets. Adambulacral plates as wide as long, or 
wider ; the furrow margin bears 8 or 7 (proximally), 6 or 5 
(distally), slender, not sharp, membrane-united spines, the 
middle ones longest, 1.5-2 mm. long ; actinal surface of plate 
with a transverse, slightly curved series of 7-9 similar spines, 
2-3 mm. long. Oral plates with a marginal series of 14 
similar spines, the proximal longest and largest, 3-3.5 mm. 
long ; actinal surface of each plate with a longitudinal series 
of 8-10 similar spines, near inner margin. Madreporite 
small and inconspicuous, half way between centre of disk and 
margin. Colour (dry), dull brown ; other specimens are light 
yellowish-brown. 
Although all four specimens have 11 rays each, the three 
from Tasmania are obviously different from the holotype, in 
their lighter colour, more conspicuous skeleton, more slender 
rays, and thinner and less noticeable membrane covering and 
uniting the spines, both abactinally and actinally. In view 
of the well-known diversity in all such particulars shown by 
the common, northern species of Crossaster (C. papposus), I 
think there is little reason to consider these differences of any 
special significance, especially since the Tasmanian specimens 
are poorly preserved. The large number, and the slenderness 
of the adambulacral and oral spines readily distinguish the 
present species from any of those previously known. 
Locs.—Between Gabo Island, Victoria, and Disaster Bay, 
New South Wales, 50-100 fathoms. This specimen has been 
selected as the holotype. 
South-east of Bruni Island, Tasmania, 150-230 fathoms. 
Genus PTERASTER, Miiller and Troschel. 
PTERASTER TETRACANTHUS,! sp. nov. 
(Plate xviii., fig. 1-2.) 
R=30 mm. ; r=24mm.; R=1.25r. General form almost 
perfectly pentagonal, moderately thick. Abactinal surface 
in such poor condition it is not possible to determine exactly 
the number of paxillar spines ; paxille somewhat numerous 
and paxillar spines long, apparently about 6. Spiracles 
1. tetpaxavOos= having four spines; in reference to the armature of the 
adambulacral plates. 
