118 THE FAUNA OF THE DEEP SEA 



characters separating these forms from the Polychastes 

 of shallow waters. 



As is the case with many other orders of animals, 

 the species of Annelida living in deep water are 

 either blind or possess eyes of a remarkably large 

 size. Genityllis oculata may be taken as an example 

 of a deep-sea annelid with large eyes. This annelid, 

 belonging to the family Phyllodocidse, was found at 

 a depth of 500 fathoms in the Celebes sea. It 

 possesses two enormous eyes which cover almost the 

 whole of the head, and there can be no doubt, from 

 the investigations of Dr. Gunn on their minute 

 anatomy, that they are perfectly functional. 



Before leaving the Annelida a brief notice must 

 be made of the very extraordinary form Syllis ramosa, 

 found parasitic on a hexactinellid sponge at depths of 

 about 100 fathoms. It is chiefly remarkable for the 

 very complicated manner it has of producing bads 

 which do not immediately become detached from the 

 parent, but form a compound network which ramifies 

 through the interstices of the sponge like the colony 

 of a Hydromedusan. 



Passing now to the sub-kingdom Mollusca, we 

 shall find that all the classes are represented in the 

 abysmal fauna. 



