40
B. K. DELL
FIG. 4. Distribution of speoies of sponges of the subfamily Rossellinae (data from
A Roeeek a&r&ca; 1 Roes& nuda;
Roeeella rawvitzae;
Koltun, 1969).
0 Roeeella villoea; 0 Scolymastra joubini; A Anoxyculyx ijimae.
1 500 to 2 000 m on the continental slope they are very rare. Spicules
however occur abundantly beyond this depth, and in places may be
commoner than they are on the shelf. Bottom currents are undoubtedly
responsible for the transfer and Koltun shows that suspended midwater spicules were collected at various levels. Thia study ahould make