Dr. J. E. Gray on Hyalonema Schultzei. 377 
and of H. cucumer may indicate that they grow in different 
situations and circumstances. 
E. cucumer most probably grows in the mud, kept in its 
place by a mooring of stones, as figured in Professor Owen’s 
late. 
The curved form of Z. aspergillum would lead one to believe 
that it most probably grows on the side of a perpendicular 
rock; but I have no proof that this is the case, except the 
form. If it grew from a horizontal surface, the top of the 
tube or cloaca would not be uppermost and the Huplectella 
in the upright position natural to all sponges and other ani- 
mals and plants that live on the bottom of the sea. 
Cc b a 
a. Euplectella aspergilum, Owen. b. Euplectella cucumer, Owen. 
ce. Semperella Schultze’, Gray, from an outline by Dr. Semper. 
This sponge cannot be the young state of Huplectella asper- 
gillum, which is also from Zebu. We have a young specimen 
of that species, not more than 2 inches high, in the British 
Museum, which was sent with the adult. It is nearly cylin- 
drical, and has distinct horizontal bundles of spicules across 
the longitudinal ones, as in the adult state of the genus, which 
are entirely wanting in Semperella. 
