REPORT ON THE ASTEROIDEA. 423 
Colour in alcohol, a bleached greyish white. 
Locality.—Station 218. Off the north coast of New Guinea, south-west of the 
Admiralty Islands. March 1, 1875. Lat. 2° 33’ 0” S., long. 144° 4’ 0” E. Depth 1070 
fathoms. Blue mud. Bottom temperature 36°°4 Fahr.; surface temperature 84°°0 Fahr. 
Genus Cnemidaster, n. gen. 
Disk small. Rays long, delicate, cylindrical, more or less rigid. Interbrachial ares 
rounded. 
Abactinal plates arranged in a single, regular, longitudinal line along the ray, covered 
with thin skin and bearing no granules or spinelets. Abactinal covering of disk composed 
of the primary apical plates, all large and convex, covered with thin skin and bearing no 
granules or spinelets. 
Supero-marginal larger than the infero-marginal plates; both series covered with skin 
and bearing no granules or spinelets (excepting a few of the infero-marginal plates in the 
interbrachial arc, which may bear appendages similar to those on the actinal intermediate 
plates). 
Actinal intermediate plates, two series present bearing small compressed sacculated 
spinelets, appressed to the ray and forming longitudinal series along the ray. 
Adambulacral plates broader than long, with a prominent angle into the furrow (all 
equally prominent), and a transverse median keel. Armature consisting of a transverse 
series of short spinelets, equidistantly spaced on the keel. 
Madreporiform body small, circular, exposed, situated external to the adjacent primary 
basal plate. 
Anal aperture distinct, excentric in position. 
No pedicellariz. 
Ambulacral tube-feet with a fleshy terminal knob, and forming two simple regular rows. 
Remarks.—This genus is distinguished from Zoroaster and the other forms in this 
family by the large skin-covered abactinal and marginal plates, devoid of spinelets or 
sranules of any form. The armature of the actinal intermediate and of the adambulacral 
plates is also characteristic. The starfish described by Perrier’ under the name of Zoroaster 
sigsbeet is perhaps more nearly related than any other form known to me; but the 
description and the figure are both insufficient to enable me to say how close the relation- 
ship may be. 
1 Bull. Mus. Comp. Zodl., Harvard, 1881, vol. ix. p.5; Nouv. Archives Mus. Hist. Nat., 2e Série, 1884, 
t. vi. p. 195, pl. iii. fig. 2. 
