Dr. J. E. Gray on Hyalonema Schultzei. 



377 



and of E, 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 

 plate. 



The curved form of E. 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 Euplectella 

 in the upright position natural to all sponges and other ani- 

 mals and plants that live on the bottom of the sea. 



a. Euplectella aspergillum^ Owen. h. Euplectella cucumer, Owen. 



c. SempereUa ScJmltzei, Gray, from an outline by Dr. Semper. 



This sponge cannot be the young state of Euplectella 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 SempereUa. 



