i66J 
RECORDS OF W.A. MUSEUM. 
CLYPEASTER TELURUS , 1 sp. nov. 
Plate XXIII. 
Test broadly oval, widest posteriorly, very flat, 96 mm. long, 
89 mm. wide and 13 mm. high ; its breadth is thus nearly .93 of its 
length, while its height is less than .14. Test thin and fragile, 
its margin only 3 mm. thick. Abactinal system at centre of test, 
but the latter slopes more abruptly posterior to the apex than it 
does anteriorly or laterally. Posterior interradial margin distinctly 
depressed below posterior radial margins. Lower surface slightly but 
very uniformly concave : the slope begins very near or at the margins 
and the mouth which is perfectly central, is nearly 4 mm. below 
(i.e. above, of course !) the lateral margins. Petaloid area 49 mm. 
long and 24 mm. wide. Anterior or unpaired petal 26 mm. long, 
12 mm. wide, rather broadly open at distal end, the converging 
poriferous areas each about 2 mm. wide. Anterolateral petals 22 
mm. long, n mm. wide, and nearly closed (open by 1 mm.) 
poriferous area about 2 mm. wide. Posterolateral petals 23 mm. 
long, 12 mm. wide, well open (by 3 mm.) : poriferous area 
2 mm. wide. Ridges between pore-pairs of unpaired petal, each 
with a single series of six or more primary tubercles. Median area 
of petals not at all abovate but as wide at middle as anywhere. 
Anal system, trigonal with rounded angles or oval, about 4.5 mm. 
broad by 3.75 mm. long ; its distal margin 10 mm. from distal mar- 
gin of test, or more than .20 of the long radius. Madreporic body 
small, only 2.5 mm. across. Genital and ocular pores indistinguis- 
able. Auricles well developed, well separated. 
Abactinal primary spines very small. Scarcely a millimetre 
long, thickened at tip. Actinal primaries 3 mm. long (those 
about mouth 4 mm.) terete and bluntly pointed. Miliary 
spines minute and abundant, slightly thickened at tip. Pedicell- 
ariae rather scarce, except around mouth and anus where tridentate 
are fairly common. Valves of tridentate rather stout, the blades 
broad, meeting only at tip; in the largest ones seen the valves are 
about .30 mm. long. Ophicephalous pedicellariae very scarce, 
small but not peculiar. 
Colour of test, abactinally, dull purplish brown of a light shade ; 
actinally the test has a slight greenish cast; abactinal spines under 
1 Gr. telouros remote; in reference to the unusual distance of the anal system 
from the margin of the test. 
