Leucosolenia lieberkiilnii.—l. Portion of the oscular tube 
with a young diverticulum. 2 and 3. The same, with older diverti- 
cula. 4. Diverticulum bearing secondary diverticula. 5. A newly 
formed (secondary) oscular tube. 0.7. Primary oscular tube. ./. 
Secondary oscular tube. (0.¢.). Ditto, in which the osculum is not 
yet formed. O. Osculum. VD. Primary diverticula. d, d', d*, d®. 
Secondary diverticula. «. Spots where the spicule-arrangement is 
confused. The arrows in 1, 2, and 8 point in the direction of the 
osculum. © 
