ECHINODERMS FROM WEST AUSTRALIA. 247 
tliree specimsns from " Garden Island, near Fremantle ; dredged," one from 
" off Fremantle," one from " Wooded Isle," and four from " Long Island." 
None of the specimens is large, the disk diameters ranging from 4 to 
8 mm. 
Ophiothrix stblligeea. 
Lyman, 1874, Bull. M. 0. Z. iii. p. 237. 
A single small specimen, from Garden Island, near Fremantle, has the disk 
-only 3 mm. across and the arms about 20 mm. long. Seven larger specimens, 
from " off Long Island,"' have the disk 3i-7 mm. across. Of these Abrolhos 
rspecimens, four show spinelets among the thorny stumps on the disk. All 
the specimens are much alike in their indistinctive, light greyish- or reddish- 
brown coloration, and show the white stripe on the upper surface of the arms. 
In the largest specimen a curious anomaly occurs in that on the proximal 
part of the arm the white stripe is black. Distally there is a white stripe 
delimited by a bldck line on each side, but as this passes towards the base of 
the arm, the black encroaches more and more on the white, and finally 
obliterates it altogether, the two black lines coalescing. Were the arms 
broken off near the base, it would be hard to believe that the brittle-star was 
really an example of stelUgera. 
Ophionereis porrecta. 
Lymau, 1860, Proc. Boston Soc. Nat. Hist. vii. p. 260. 
The occurrence of this species in the Abrolhos is most interesting, as it 
■does not seem to be common anywhere in the Bast Indies and is not yet 
Jcnown from the mainland const of Australia, although it is not i-are at the 
Murray Islands, in the Torres Strait region. There are five specimens at 
hand from Wooded Island and two from Pelsart. One of the latter is only 
4 mm. across the disk and has the arms about 20 mm. long. The disk is 
nearly pure white, save for the dark brown distal tips of the radial shields. 
The other half dozen specimens are 8-12 mm. across the disk. 
Ophiocoma brevipes var. variegata. 
Ophiocoma variegata E. A. Smith, 1876, Ann, Mag. Nat. Hist. (4) xviii. p. 39. 
Ophiocoma hrevipes yur. variegata H. L. Clark, 1921, Echiuoderms of Torres Strait, 
p. 130. 
It is rather remarkable that this widespread and variable Opldocoma 
should be the only representative of the family taken at the Abrolhos. It 
was found both at Wooded Island (8 specimens) and at Long Island, Pelsart 
Group (4 specimens). The specimens range in disk-diameter from 12 to 
29 mm. All are evidently to be referred to the variety variegata, but two 
have the black-spotted disk of the form that has been called O.doderleini and 
two have the reticulated disk of the so-called 0. dentata. None is like 
0. insularia or the typical 0. brevipes. 
