152 ] 
RECORDS OF IV. A. MUSEUM. 
OPHIUROIDEA. 
Although four of the nine species of ophiurans appear to be 
undescribed and one of these requires the formation of a new genus, 
the collection from the Western Australian Museum is remarkable 
for what it does not contain, to nearly as great a degree as for what 
composes it. The ophiurans of West Australia have recently been 
the subject of a paper by Koehler i based on the collection made by 
Michaelsen and Hartmeyer in 1905. That collection contained 28 
species, of which only three were considered as previously undes- 
cribed ; one of these was an Ophiacantha and the other two 
belonged to Ophiothrix, both large, diversified and widespread 
genera. A fourth species was subsequently described as new by 
Doderlein an astrophyton of the genus Astroboa. Of the 28 
species, only 3 are in the collection before me. Of the 14 genera 
collected by Michaelsen and Hartmeyer, only 4 are in this collec- 
tion; such common genera as Amphiura, Ophiactis, Ophionereis, 
Ophiocoma and Ophiacantha are entirely unrepresented. On the 
other hand the two collections contrast with each other sharply in 
the fact that only one of Michaelsen’s and Hartmeyer’s species was 
a Euryalid while fi ve of the nine species before me represent that 
group. It would be hard to collect two series of Ophiurans from 
the same region which would difler more strikingly from each other 
than do the two under discussion. Nor is it easy to suggest any 
reason for such an extraordinary difference. Possible further 
studies, made on the ground, may exphiin the matter.® 
PECTINURA DYSCRITA. 
H. L. Clark, igog. Thetis Echinoderms. Mem. Aust. Mus., vol. 4, p. 534. 
This species, previously known only from New South Wales, 
is represented by a single specimen in poor condition. 
Between Fremantle and Geraldton, W.A. One specimen. 
No. 4929. 
1 Koehler, 1907. Die Fauna Siidwest-Australiens ; Ophiuroidea, vol. i, pp. 
241-254. 
2 Doderlein, T911. Tiber japanische nnd andeie Euryalae, p. 82. 
3 The explanation of the difference between these two collections appears to be 
simple. The collection sent to Mr. Clark was entirely composed of speci- 
mens trawled by the Endeavour , chiefly in depths approaching too fathoms. 
Drs. Michaelsen and Hartmeyer obtained their specimens by dredging in 
comparative!}' shallow water in shelten d localities, — W. B. A. 
